Abstract: The annual deficits of N, P, K, Ca, Mg and Si in a Phyllostachys pubescens ecosystem of southern Sichuan were calculated based on expected and realized yield in this paper. Results showed that: (1)With annual yield at 22.5 t/hm2, the total annual output of all six nutrients was 216.78 kg/hm2, of which contribution of N, Si, K, Ca, Mg and P were 93.13, 57.61, 38.04, 11.39, 8.33 and 8.28 kg/hm2 respectively, and the 73.3 kg/hm2 per annual would reduce nutrient loss through by returning bamboo leave back to the field. (2)According to the realized yield of 9 t/hm2, the deficit was 29.91 % for Si, 27.19 % for P, 22.97 % for N, 8.51 % for Mg, and 7.60 % for K in descending order. (3)After analyzing the elements in soil and their deficiency, two conclusions could be drawn that application of P fertilizer has the most direct effect for improving P.pubescens production, and supplementation of nutrients such as K, Si and Mg is essential for preventing fertility decline and maintaining the sustainability of P.pubescens production.