The ecological environment is fragile in Yulin city.The distribution and change of the net primary productivity of vegetation has great influence on it.We analyzed spatial and temporal variation characteristics of NPP in Yulin city by markov transfer matrix and spatial overlay analysis based on the 2000,2005 and 2010 NPP data.The results show that:(1)The distribution of NPP in Yulin city gradually increases from the northwest to the southeast.(2)The annual NPP shows a significant upward trend from 2000 to 2...