It is important to study the nutrition requirement of Takifugu obscurus because the puffer is a precious and potential species for intensive aquaculture .A 12-week growth experiment was conducted in indoor concrete ponds to determine the optimum protein level for the growth of juvenile T .obscurus , at the temperature of 24 - 26 ℃.White fish meal was used as the sole protein source to formulate isocaloric experimental diets at six protein levels (35 %, 40 %, 45 %, 50 %, 55 %, 60 %).Weight gain and feed efficiency of fish improved with increasing dietary protein level up to 50 % and reached a plateau above this level .Weight gain of fish fed 50 % protein diet was significantly higher (P <0 .05)than that of fish fed 35 %, 40 %and 45 %protein diet , but not significantly different from that of fish fed 55 % and 60 % protein diet (P >0 .05).The protein efficiency ratio tended to decrease with increasing dietary protein level , but there is no significant difference among the diets containing 35 %, 40 %and 50 % protein levels (P >0 .05).Dietary protein requirement using broken-line model was estimated at approximately 49 % and 46 % for maximum growth and maximum protein utilization , respectively .Therefore , it is suggested that the optimum dietary protein level for juvenile T .obscurus should be 46 %-49 %.The result is similar to that of tiger puffer T .rubripes .