Soil degradation induced by human activities together with natural factors has been attracting increasing attention in the world.Many researchers have studied this issue from differentangles.This paper analyzes soil degradation from the view of institutional economics.The authors argue that institutions affect soil degradation by influencing farm households'behaviors.Firstly,institutions influence farm households investing in production.Secondly,institutions determine selection of patterns of farming systems and technologies.A basic research methodology for the study on how institutions influence soil degradation is thus discussed in the paper.