Pioneer White

bayucca is correct it's Pioneer White.

I absolutely not have the impression that you are a beginner, Nowan!

oh no! dayucca im not an expert, still a beginner :)
sorry for the wrong id Sachin.

Thanks bayucca for sharing useful links to get perfect idea about species,
Updating the ID, thanks a lot,

I know I play now a very risky game, challenging an ID from an Asian expert which I am definitely not. I was first looking in Appias sp., noticed then the ID Common Gull and was missing this dominant black large stripe on the forewing. I know that there are different seasonal forms of Pioneers and also within the genus and species there is a great variability, so, please, check yourself and verifiy...
http://en.wikipedia.org/wiki/Anaphaeis_a...
http://www.treknature.com/gallery/Asia/I...
http://www.treknature.com/gallery/photo2...
http://www.flickr.com/photos/davidlev/40...
http://www.google.ch/imgres?q=Anaphaeis+...
http://photo.net/photodb/photo?photo_id=...

Thanks Nuwan for ID help,