This experiment was conducted to determine the effects of dietary supplementation of rumen-protected lysine (RPLys) and rumen-protected methionine (RPMet) on performance of lactating water buffalo. Fifteen healthy water buffaloes in early lactation were selected, and according to species, milk yield, calving time and similar parity, the experimental animals were randomly divided into 5 groups, and 3 lactating water buffaloes for each group, using 5×5 Latin square design with 5 periods (each period lasted for 21 days) and 5 groups, i.e. control 1 (basal diet 1, crude protein level of concentrate=16%), control 2 (basal diet 2, crude protein level of concentrate=20%), treatment 1 (basal diet 1+RPLys 40 g/d), treatment 2 (basal diet 1+RPMet 15 g/d), and treatment 3 (basal diet 1+RPLys 30 g/d+RPMet 6 g/d). The results showed as follows: 1) there was no significant difference in milk yield of lactating water buffalo among all treatments (P>0.05), but supplementation of RPLys or RPMet could increase the milk yield of lactating water buffalo to some extent and supplementation of RPLys had better effects than RPMet and RPMet+RPLys supplementation. Compared with control 1 and control 2, the supplementation of RPLys increased the milk yield by 10.0% and 5.9% (P>0.05). 2) There was no significant difference in dry matter intake of lactating water buffalo among all treatments (P>0.05). 3) The supplementation of RPLys and RPMet could improve milk protein rate, milk lactose rate, and milk total solid and milk non-fat solid contents of lactating water buffalo. Compared with control 1, the milk protein rate of the treatments with supplementation of RPLys, RPMet and RPLys+RPMet were increased by 29.0% (P>0.05), 36.8% (P＜0.05) and 54.3% (P＜0.05), respectively; and compared with control 2, the milk protein rate of the treatments with supplementation of RPLys, RPMet and RPLys+RPMet were increased by 3.9% (P>0.05), 10.2% (P>0.05) and 24.4% (P>0.05), respectively. Therefore, dietary RPLys and RPMet supplementation, to some extent, improve performance and milk quality of lactating water buffalo.［Chinese Journal of Animal Nutrition, 2010，22（5）:1445-1450］