diff --git a/sketch.js b/sketch.js
index 05273e6..92ea9ac 100644
--- a/sketch.js
+++ b/sketch.js
@@ -8,37 +8,79 @@ let powerUps = [];
 let deathZoneY = 600;
 
 let spriteSheets = {};
-let background_sky;
 
 function preload() {
-  // 여기에 sprite들을 preload (ex: mario = loadImage("..."))
-  spriteSheets.backgorunds= loadImage("assets/Mario-Background.png");
+  spriteSheets.backgrounds= loadImage("assets/Mario-Background.png");
   spriteSheets.characters = loadImage("assets/Mario-Character+Item.png");
   spriteSheets.specialweapon = loadImage("assets/Mario-Enemy.png");
   spriteSheets.tileset = loadImage("assets/Mario-Tileset.png");
 }
+class Background {
+  constructor(dayImg, nightImg) {
+    this.bgDay = dayImg;
+    this.bgNight = nightImg;
+    this.mode = 'day';
+    this.currentImg = this.bgDay;
+    this.tileW = dayImg.width;
+    this.tileH = dayImg.height;
+  }
 
+  setMode(mode) {
+    if (mode === "day") {
+      this.mode = "day";
+      this.currentImg = this.bgDay;
+    } 
+    else if (mode === "night") {
+      this.mode = "night";
+      this.currentImg = this.bgNight;
+    } 
+    else {
+      console.log("error");
+    }
+  }
+  modeChange(){
+    this.setMode(this.mode === "day" ? "night" : "day");
+  }
+  draw() {
+    for (let y = 0; y < height; y += this.tileH) {
+      for (let x = 0; x < width; x += this.tileW) {
+        image(this.currentImg, x, y);
+      }
+    }
+  }
+}
+
+let backgroundManager;
 function setup() {
   createCanvas(800, 600);
-  const bgsource = spriteSheets.backgorunds;
-  background_sky = createImage(400,300);
-  background_sky.copy(bgsource,
-     514, 1565, 
-     512, 512, 
-     0, 0, 
-     400,300);
+  const bgsource = spriteSheets.backgrounds;
+  const bgDay = createImage(512, 512);
+  bgDay.copy(bgsource, 
+    514, 1565, 
+    512, 512, 
+    0, 0, 
+    512, 512);
+  const bgNight = createImage(512, 512);
+  bgNight.copy(bgsource, 
+    514, 5721, 
+    512, 512, 
+    0, 0, 
+    512, 512);
+  backgroundManager = new Background(bgDay, bgNight);
   
   
 }
 
 function draw() {
-  for (let y = 0; y < height; y += background_sky.height) {
-    for (let x = 0; x < width; x += background_sky.width) {
-      image(background_sky, x, y);
-    }
-  }
+  backgroundManager.draw();
 
   // 임시 바닥
   fill(100);
   rect(0, groundY, width, 100);
 }
+
+function keyPressed(){
+  if(key === ' '){//spacebar(임시시)
+    backgroundManager.modeChange();
+  }
+}