Abstract: This paper summarizes the progress of the cause analysis on climate changes in Southwest China in recent years.The cause analysis has been conducted from two aspects:natural and human factors.The natural factors include sea surface temperature, changes in the main weather infection system, solar activities, and changes in snow coverage.The human factors include emission of greenhouse gas and atmospheric aerosol, changes in land utilization, urbanization, and urban heat island effects.This paper also points out that the factors leading to the observed climate changes are complex and some analysis have been based on uncertainties.