Hi

Is Percentage based salary LEGAL for H1B VISA ? Ex: (70-30) like this.

Don't understand your question... who gets 70? And who gets 30?

Iam generally asking is this LEGAL for H1B VISA.

I am planing to transfer my H1B and getting Percentage based offers from different employers.

You do not have to worry about what "%" you get from your petitioner (H1 visa Sponsor).
What you need ( and your sponsor as well) is that you get paid an "Amount" greater than or equal to that petitioned on your LCA or form I129. It clearly states the minimum salary you will be paid annually.

Hope that helps , let me know of further questions if any

Thanks for the Information. I have one more question.

In '%' basis the is employee need to pay employeer tax also or who need to pay?