Abstract: After irrigation and fertilization, the photosynthetic rate of Aneurolepidium chinense community were measured by means of assimilation chamber under field condition, The results are as follows:1. It were measured 23 days after treatments, height of leaf layer of irrigation and irrigation add fertilizatiin were raised 8% and 9%; LAI of community were increased 68.97% and 99.93%; net photosynthesis per day were 2.48 and 3.76 times than contrast respectively; the biggest photosynthetic rate were 2.82 and 3.12 times than contrast respectively.2. After irrigation and fertilization, the type of diurnal change of photosynthetic rate of Aneurolepiium chinense community still were "double peak" curve. They were same with contrast. Only which of irrigation add fertilization (13 days after treatments) was "single peak" type, it hadn't a reduction at the noon time. Showing the type of diurnal change photosynthetic rate may was changed when the conition of water and ferility were better.3. When the temperature and relative humidity were worse or the treatment time was longer, the effects of treatment were apparent. At first measurement, the net photosynthesis per day of irrigation and irrigation add fertilization community were 1.26 and 1.17 times than contrast respecctively. At second measurement, they were 1.4 and 1.84 times respectively. At third measurement, they were 2.48 and 3.76 times respectively.