1.Login to blogger dashboard-->Layout > Page Elements

2.Click on 'Add a Gadget'.

3.Select 'HTML/Javascript' and add the code given below and click save.

Note : You must replace YOURBLOG with your real blog name.

You can Customize other values as your choice ;

var nMaxPosts = 15; - This code sets the number of posts in this widget.

var sBgColor; - If you want to set background color then change this code to var sBgColor= grey;

var nWidth; - Modify this code to change the width to var nWidth= 100px;

var nScrollDelay = 175; - This code is used to set the speed of scrolling. Lesser the no, higher the speed of scrolling.

var sDirection="left"; - This code sets the direction of scroll. left = Right to left; Right = Left to right; Up = Down to up; Down = Up to down

var sBulletChar="»»"; - This bullet appears before each post link in this widget. You can replace this to any other bullet.

Now you are done.