Edit in JSFiddle

 @keyframes left_move {
   from {left: 0px;}
   20%  {left: 200px;}
   60%  {left: 50px;}
   75%  {left: 100px;}
   to   {left: 0px;}
 }

div {
   width: 100px;
   height: 32px;
   margin-top:5px;
   background: pink;
   position: relative;
   animation-name: left_move;
   animation-duration: 5s;
   animation-iteration-count: infinite;
}
 
 .ex1 { 
   animation-delay: 0;
 }
 
 .ex2 { 
   animation-delay: 500ms;
 }
 .ex3 { 
   animation-delay: 1.5s;
 }
 .ex4 { 
   animation-delay: -2.5s;
 }


<!DOCTYPE html>
<html lang="ko">
  <head></head>
  <body>
    <div class="ex1">0</div>
    <div class="ex2">500ms</div>
    <div class="ex3">1.5s</div>
    <div class="ex4">-2.5s</div>
  </body>
</html>