diff --git a/src/models/blob.rs b/src/models/blob.rs
index 9370d3c..98e57f0 100644
--- a/src/models/blob.rs
+++ b/src/models/blob.rs
@@ -17,7 +17,7 @@ pub struct Blob {
 impl Blob {
     /// 从源文件新建blob对象，并直接保存到/objects/中
     pub fn new(file: &Path) -> Blob {
-        let data = fs::read_to_string(file).expect("无法读取文件");
+        let data = fs::read_to_string(file).expect(format!("无法读取文件：{:?}", file).as_str());
         let hash = calc_hash(&data);
         let blob = Blob { hash, data };
         blob.save();
diff --git a/src/models/commit.rs b/src/models/commit.rs
index 22ef6f3..f9cdbc9 100644
--- a/src/models/commit.rs
+++ b/src/models/commit.rs
@@ -21,7 +21,7 @@ pub struct Commit {
 
 impl Commit {
     pub fn new(index: &Index, parent: Vec<Hash>, message: String) -> Commit {
-        let tree = Tree::new(index);
+        let mut tree = Tree::new(index);
         let tree_hash = tree.save();
         Commit {
             hash: "".to_string(),
diff --git a/src/models/tree.rs b/src/models/tree.rs
index 4d32416..22b0271 100644
--- a/src/models/tree.rs
+++ b/src/models/tree.rs
@@ -1,6 +1,8 @@
+use std::{collections::HashMap, path::PathBuf};
+
 use serde::{Deserialize, Serialize};
 
-use crate::store;
+use crate::{store, utils::util};
 
 use super::{index::Index, object::Hash};
 /*Tree
@@ -21,14 +23,76 @@ pub struct Tree {
     pub entries: Vec<TreeEntry>,
 }
 
-impl Tree {
-    pub fn new(index: &Index) -> Tree {
-        // XXX wait for index to be implemented
-        Tree {
-            hash: "".to_string(),
-            entries: Vec::new(),
+/** 将文件列表保存为Tree Object，并返回最上层的Tree */
+fn store_path_to_tree(path_entries: &Vec<PathBuf>, current_root: PathBuf) -> Tree {
+    let get_blob_entry = |path: &PathBuf| {
+        let file_path = util::get_working_dir().unwrap().join(path);
+        let blob = super::blob::Blob::new(&file_path.clone());
+        let mode = util::get_file_mode(&path);
+        let filename = path.file_name().unwrap().to_str().unwrap().to_string();
+        let entry = TreeEntry {
+            filemode: (String::from("blob"), mode),
+            object_hash: blob.get_hash(),
+            name: filename,
         };
-        unimplemented!("Tree::new");
+        entry
+    };
+    let mut tree = Tree {
+        hash: "".to_string(),
+        entries: Vec::new(),
+    };
+    let mut processed_path: HashMap<String, bool> = HashMap::new();
+    for path in path_entries.iter() {
+        // 判断是不是直接在根目录下
+        let in_path = path.parent().unwrap() == current_root;
+        // 一定是文件，不会是目录
+        if in_path {
+            let entry = get_blob_entry(path);
+            tree.entries.push(entry);
+        } else {
+            if path.components().count() == 1 {
+                continue;
+            }
+            // 拿到下一级别目录
+            let process_path = path
+                .components()
+                .nth(0)
+                .unwrap()
+                .as_os_str()
+                .to_str()
+                .unwrap();
+            if processed_path
+                .insert(process_path.to_string(), true)
+                .is_some()
+            {
+                continue;
+            }
+
+            let sub_tree = store_path_to_tree(path_entries, process_path.into());
+            let mode = util::get_file_mode(&util::get_working_dir().unwrap().join(process_path));
+            tree.entries.push(TreeEntry {
+                filemode: (String::from("tree"), mode),
+                object_hash: sub_tree.get_hash(),
+                name: process_path.to_string(),
+            });
+        }
+    }
+    tree.save();
+    tree
+}
+
+impl Tree {
+    pub fn get_hash(&self) -> String {
+        self.hash.clone()
+    }
+    pub fn new(index: &Index) -> Tree {
+        let file_entries: Vec<PathBuf> = index
+            .get_tracked_files()
+            .iter_mut()
+            .map(|file| util::to_root_relative_path(file))
+            .collect();
+
+        store_path_to_tree(&file_entries, "".to_string().into())
     }
 
     pub fn load(hash: &String) -> Tree {
@@ -39,10 +103,64 @@ impl Tree {
         tree
     }
 
-    pub fn save(&self) -> String {
+    pub fn save(&mut self) -> String {
         let s = store::Store::new();
         let tree_data = serde_json::to_string_pretty(&self).unwrap();
         let hash = s.save(&tree_data);
+        self.hash = hash.clone();
         hash
     }
 }
+
+#[cfg(test)]
+mod test {
+    use std::path::PathBuf;
+
+    use crate::models::blob::Blob;
+    use crate::models::index::FileMetaData;
+    use crate::utils::util;
+    #[test]
+    fn test_new() {
+        util::setup_test_with_clean_mit();
+        let mut index = super::Index::new();
+        for test_file in vec!["b.txt", "mit_src/a.txt"] {
+            let test_file = PathBuf::from(test_file);
+            util::ensure_test_file(&test_file, None);
+            index.add(
+                test_file.clone(),
+                FileMetaData::new(&Blob::new(&test_file), &test_file),
+            );
+            index.add(
+                test_file.clone(),
+                FileMetaData::new(&Blob::new(&test_file), &test_file),
+            );
+        }
+
+        let tree = super::Tree::new(&index);
+        assert!(tree.entries.len() == 2);
+        assert!(tree.hash.len() != 0);
+    }
+
+    #[test]
+    fn test_load() {
+        util::setup_test_with_clean_mit();
+        let mut index = super::Index::new();
+        let test_files = vec!["b.txt", "mit_src/a.txt"];
+        for test_file in test_files.clone() {
+            let test_file = PathBuf::from(test_file);
+            util::ensure_test_file(&test_file, None);
+            index.add(
+                test_file.clone(),
+                FileMetaData::new(&Blob::new(&test_file), &test_file),
+            );
+        }
+
+        let tree = super::Tree::new(&index);
+        let tree_hash = tree.get_hash();
+
+        let loaded_tree = super::Tree::load(&tree_hash);
+        assert!(loaded_tree.entries.len() == tree.entries.len());
+        assert!(tree.entries[0].name == loaded_tree.entries[0].name);
+        assert!(tree.entries[1].name == loaded_tree.entries[1].name);
+    }
+}