I'm getting my adjustment of status through marriage to a US citizen, my i94 is expired already, do I need to feel I485a?

You would only submit Form I-485A if you are grandfathered under INA 245(i). Form I-485A is not typically filed in a marriage-based adjustment of status case. You can read more about adjustment of status at http://myattorneyusa.com/adjustment-of-immigration-status.