In Chinese mitten crab ( Eriocheir sinensis ) , the gonadal development of juvenile crab correlates with the total protein level in the hepatopancreas and hemolymph. The total protein level in the hepatopancreas of the juvenile crab is ( 121. 17 ? 44. 50) mg#g- 1 for female and ( 89. 43 ? 21. 86) mg#g- 1 for male respectively. But the protein level in the hepatopancreas of the precocious crab drops to ( 81. 08 ? 5. 84) mg#g - 1 for female and 70. 58 ? 9. 90mg#g- 1 for male respectively. Simultaneously, the rate between hepatopancreas and body weight of female juvenile crab is descending f rom 8. 18% to 3. 90% . The hemolymph total protein level of the female juvenile crab is ( 99. 55 ? 12. 06) mg#mL- 1, it is higher than that of the female precocious crab. The hemolymph total protein level of the male juvenile crab is similar to that of the male precocious crab. The total protein level in the hepatopancreas of the female adult crab is higher than that of the female precocious crab, but they have a approximate value of the total protein level in the hemolymph. The total protein level in the hemolymph and hepatopancreas is not different from the male adult crab and the male precocious crab.