Losses of nitrogen and phosphorus from bamboo forest in Yangtze River Delta were estimated on the basis of analysing intensive cultivation area, fertilization, and fertilizer loss rate. The results showed that annual loss of nitrogen and phosphorus amounted to 3795~6067 t and 828~104 t, respectively, in which, those from Zhejiang Province were 3573~5713 tN and 779~1039 tP, accounting for 94% of the total loss. The loss of nitrogen from bamboo forest (9.8~15.6 kg/hm²) was much lower than that from farmland (57.4 kg/hm²) in Zhejiang Province. However, the loss of phosphorus from bamboo forest (2.1~2.8 kg/hm²) was higher than that from farmland (1.7 kg/hm²). In some intensive cultivation area of bamboo, the annual loss of nitrogen and phosphorus amounted to 162.9~195.5 and 7.4 kg/hm², respectively. Since bamboo forests usually grow upriver or on the river or lake banks, the loss of N and P could directly increase the risk of water pollution.