diff --git a/src/_Problems_/max-array-sum/index.js b/src/_Problems_/max-array-sum/index.js
new file mode 100644
index 00000000..e9732db4
--- /dev/null
+++ b/src/_Problems_/max-array-sum/index.js
@@ -0,0 +1,45 @@
+function maxArraySum(array, n) {
+    if (array.length == 0) {
+        return "null as the length of array is nil.";
+    }
+    else if (array.length < n) {
+        var str = "null as the length of subarray is less than " + n + ".";
+        return str;
+    }
+    else if (array.length == n) {
+        var sum = array.reduce(function (a, b) {
+            return a + b;
+        }, 0);
+        return sum;
+    }
+    else if (array.length > n) {
+        var i, j, max;
+        for (i = 0; i < 1; i++) {
+            var temp = [];
+            for (j = i; j < i + n; j++) {
+                temp.push(array[j]);
+            }
+            var sum = temp.reduce(function (a, b) {
+                return a + b;
+            }, 0);
+            max = sum;
+        }
+        for (i = 1; i <= array.length - n; i++) {
+            var temp = [];
+            for (j = i; j < i + n; j++) {
+                temp.push(array[j]);
+            }
+            var sum = temp.reduce(function (a, b) {
+                return a + b;
+            }, 0);
+            if (sum > max) {
+                max = sum;
+            }
+        }
+        return max;
+    }
+}
+
+module.exports = {
+    maxArraySum,
+};
\ No newline at end of file
diff --git a/src/_Problems_/max-array-sum/max-array-sum.test.js b/src/_Problems_/max-array-sum/max-array-sum.test.js
new file mode 100644
index 00000000..c55667c2
--- /dev/null
+++ b/src/_Problems_/max-array-sum/max-array-sum.test.js
@@ -0,0 +1,15 @@
+const { maxArraySum } = require('.');
+
+describe('Max Array Sum', () => {
+  it('Should return 10', () => {
+    expect(maxArraySum([1, 5, 2, 3, 4], 3)).toEqual(10);
+  });
+
+  it('Should return 1', () => {
+    expect(maxArraySum([1, 2, 4], 4)).toEqual("null as the length of subarray is less than 4.");
+  });
+
+  it('Should return 120', () => {
+    expect(maxArraySum([], 2)).toEqual("null as the length of array is nil.");
+  });
+});