I wanna create a new user in salesforce development. But i am unable to do this. there is no any way to perform this task. Would any one tell me please how will i create new user in salesforce.
You mean in the web interface? Click your name (upper right corner of the page), then "Setup" and type "Users" in the search box. Finally - hit "New user"button.
The fastest way to reach this page is to go to
https://na5.salesforce.com/005/e (use your SF instance, mine is on "na5").
If you're looking for Apex script for user creation - try for example Creating a user with DML
If you need to create many users in one go you could look into the DataLoader tool for a start. Start with exporting a list of your existing users though so you'll have all the field names and values handy.