Manually, it will take a lot of time to import category one by one. So, This post will explain "how to import - export all categories of one setup to new setup in magento through extension".

here you can download import- export extension.
Paste app and skin folder to magento new setup after downloading.
then go to backend & you will see import/export options in the menu bar.

Export All Categories (step by step)

step 1- login to admin pagel & click -> ( Mageworks->Export)

step 2- Click on “Categories” link.

step 3- Go to magento setup ( path: /var/export/category ). Here you can see “categories.csv” file.

Import All Categories (step by step)

step 1- Copy category.csv file from ( path: /var/export/category/categories.csv ) & paste it to the /var/import/category folder of new setup.

step 2- Go to the backend (administrative panel) & Click on Mageworks->Import.

step 3- Under the Import Profiles -> “Categories”-> click on submit button.