Hi , I have no idea for this,
I am displaying images from db dynamically, by clicking gallery link I dislay all the images, but I want to display by folder type for a set of images. Can anyone help for me?

Like, In one table I have gallery category, In another table I have images, based on the gallery category ID I want to display images. I will show the cat_ID, by clicking that I want to display the particular cat_ID Images. How to do?

Well you are currently displaying images from your database.

Instead of that, display your categories from your database.

Display these as a collection of links.

Wach link can have a querystring on the end eg:

<a hre="http://www.mysite.com/mypage.aspx?cat=1">Category 1</a>
<a hre="http://www.mysite.com/mypage.aspx?cat=2">Category 2</a>
<a hre="http://www.mysite.com/mypage.aspx?cat=3">Category 3</a>

Then when users click on the link, in mypage you read in the category id from the querystring and use this to construct your sql statement to only select images in that category and then display those as you are doing now.

I have no idea what technologies or langues you are using by the way as you just posted this in Web Development.

Good, I `m using PHP , HTML5,PhpMyadmin DB,
Can you tell me more about next step?

You say that "I am displaying images from db dynamically"

As I said the next step is to instead of that, display your categories from your database.

Are you able to do that - can you show me your existing code for displaying images from db dynamically?