I married a man from pakistan in 2005. He got his green card in 2007 and his permanent card in 2009. Now he says he is home sick and is moving back. He asked me to come along but I refused so we are getting divorced. I do not want it but he is not listening to me. How can I cancel his green card?

Nothing you can do... if you are not happy with marriage, simply get divorce and move on. Good luck.