I am making iphone application. In that I am integrating Twiiter using OAuth.
My question is I want my own login page and not provided by twitter as in new OAuth integra
No you cannot create your own login page.
OAuth is a mechanism that allows users to access a service via a 3rd party without sharing their credentials and if you were able to create your own login page, you would handle the credentials yourself and that's not what Twitter wants.
Edit: Twitter offers an alternative called xAuth. Here is a statement from TweetDeck. If you want to use xAuth you will have to register your application with Twitter to obtain a key to sign your requests. More information here