diff --git a/Diagonal_Sum_of_Tree.cpp b/Diagonal_Sum_of_Tree.cpp
new file mode 100644
index 0000000..3bb0190
--- /dev/null
+++ b/Diagonal_Sum_of_Tree.cpp
@@ -0,0 +1,76 @@
+// C++ Program to find diagonal
+// sum in a Binary Tree
+#include <bits/stdc++.h>
+using namespace std;
+
+struct Node
+{
+	int data;
+	struct Node* left;
+	struct Node* right;
+};
+
+struct Node* newNode(int data)
+{
+	struct Node* Node =
+			(struct Node*)malloc(sizeof(struct Node));
+	
+	Node->data = data;
+	Node->left = Node->right = NULL;
+
+	return Node;
+}
+void diagonalSumUtil(struct Node* root,
+				int vd, map<int, int> &diagonalSum)
+{
+	if(!root)
+		return;
+		
+	diagonalSum[vd] += root->data;
+
+
+	diagonalSumUtil(root->left, vd + 1, diagonalSum);
+
+	diagonalSumUtil(root->right, vd, diagonalSum);
+}
+
+void diagonalSum(struct Node* root)
+{
+
+	
+	map<int, int> diagonalSum;
+	
+	diagonalSumUtil(root, 0, diagonalSum);
+
+	map<int, int>::iterator it;
+		cout << "Diagonal sum in a binary tree is - ";
+	
+	for(it = diagonalSum.begin();
+				it != diagonalSum.end(); ++it)
+	{
+		cout << it->second << " ";
+	}
+}
+
+// Driver code
+int main()
+{
+	struct Node* root = newNode(1);
+	root->left = newNode(2);
+	root->right = newNode(3);
+	root->left->left = newNode(9);
+	root->left->right = newNode(6);
+	root->right->left = newNode(4);
+	root->right->right = newNode(5);
+	root->right->left->right = newNode(7);
+	root->right->left->left = newNode(12);
+	root->left->right->left = newNode(11);
+	root->left->left->right = newNode(10);
+
+	diagonalSum(root);
+
+	return 0;
+}
+
+
+