Abstract: Digestive tube index and the activity distribution of pepsin and trypsin In NEW GIFT Tilapia (Oreochromis niloticus) were studied.It was found that Oreochromis niloticus had intestinal length (IL) /total length (TL) of 4.921 ± 0.187, intestinal weight (IW) /body weight (BW) of 0.018 ± 0.002, and hepatopancreas weight (HW) /BW of 0.014±0.003, splanchnic weight (SW) /BW of 0.039±0.007.The result showed that Oreochromis niloticus was a kind of heterophagous fish with partial phytophagy food habit.After starvation and refeeding, Pepsin activity increased to a maximum of 167.872Uat 12h.However, it reduced from12hto 96h;especially 12hto 24h, the decrease rate was significant.Trypsin activities of hepatopancreas, foregut, midgut and hindgut were tested.The specific activity of trypsin in four organs was in the order of hepatopancreas<midgut<foregut<hindgut.The Trypsin activities in four parts increased up to a maximum during the first stage, then decreased smoothly.trypsin activity of each tissues was significant difference (P<0.05) 。