This is a good question, but you really do not need to cite your professor's lecture in a paper. Every professor that I have spoken to or graded for was unanimous. Lectures do not need to be cited. Part of the reason for this is because what lectures offer is basic information that everyone in the field knows. However, there is an exception. If your professor has written a book or an article on this topic, then you should go back to the book or article and cite it properly, as you would do with any book or article.

If you believe that you should absolutely cite your professor's lecture, follow the link and it will give you MLA lecture citation. Just in case, ask your professor. Citing a lecture may be unnecessary.

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.