If I understand this correctly, you are writing a paper and you want to cite your professor as one of your sources. I assume that what you want to cite is a lecture that he or she gave.
If that's the case, follow the first link I have provided below for some instructions on how to do that. Scroll down to "Speeches, Lectures, or Other Oral Presentations."
The basic format is
Name of speaker, title (if any), name of meeting, organization presenting it, location, date. The last thing you put is some sort of descriptor like "class lecture."
The first link gives you a general idea of how to do this, along with links to all MLA formats. The second link tells you exactly how to do a class lecture specifically.