National Salaries. According to the BLS, all postsecondary law teachers made an average annual salary of $108,760 in May 2011. The middle 50 percent of law professors took in between $57,940 and $148,200, and the median salary was $93,330 per year.alaries by Rank. Law professors took in the most of all disciplines in all levels of professor rank, according to CUPA-HR. Full professors in all types of surveyed institutions took in $135,187, while associate professors made $103,109 per year.