Abstract: The net primary productivity of vegetation of Wuhan City in 2009 was estimated by the CASA model with measured photosynthetic active radiation data,normalized difference vegetation index and Land Cover data of Moderate Resolution Imaging Spectroradiometer(MODIS),as well as meteorological data etc.The results shows that the NPP of the unit area of vegetation is 464.19 gC·m-2·a-1.And,the accumulated NPP of June to August is 56.8% of the gross NPP of the full year,which is the highest compare to that of other months.On the contrary the accumulated NPP of December to February is 5.6% of the gross NPP,which is the lowest compare to that of other months.Further more,the gross NPP of Huangpi is larger than 1 000 gC·m-2·a-1 due to its large area of forest cover.Conversely,the gross NPP of peri-urban area is lower than 400 gC·m-2·a-1 because of the shortage of vegetation cover.