If we marry in mexico he has no green card so can in still leave with me to cross the line to us

Are you a US Citizen? What are your plans after marriage?

The simple answer is "no" and not for at least a year, if not (much) more. If you are a US citizen, consider the Fiancee Visa option, will bring him here faster than a marriage-based petition. Consult with an experienced lawyer in private over a teleconference or Skype to properly learn the procedure, options available to you & best way to attain your objectives.

Short answer is no, at least not immediately. After marrying, you will need to go through a series of steps to apply for an immigrant visa, which will allow your spouse to lawfully enter the United States. Each of these steps takes time, requires proper documentation, and carries expense. It is advisable that you consult with a licensed attorney experienced in immigration law to make sure he is eligible for an immigrant visa, especially if he has had any prior immigration or criminal issues. Best wishes to you and your fiance.