Abstract: Objective: To evaluate bioavailability of protein hydrolysate- citrate calcium( PHC- Ca) from shrimp shell.Method: 4 weeks SD rats were randomly divided into 6 groups with 10 rats in each,and then gavaged with PHC- Ca,Ca CO3,calcium citrate,calcium gluconate,shrimp shell powder based on low calcium diet and low calcium control diet for 8 weeks.The calcium gavage dose to rats was 66.5 mg Ca /( kg·d).Calcium metabolic test was conducted by the end of the forth week.Moreover,the index related to serum and bone were assayed by the end of the 8th week.Result: The rats' growth index in low calcium was lower than other group except Ca CO3.The calcium absorption rate of PHC- Ca group was remarkable high than other groups except low calcium control.Furthermore,the level of ALP,BGP,in serum indicated that PHC- Ca improved calcium absorption in serum level significantly( p < 0.05). Moreover,the bone index showed the bioavailability in PHC- Ca group( p < 0.05).Conclusion: PHC- Ca prepared from shrimp shell could be promote calcium absorption,its bioavailability was better than same calcium content of calcium citrate and shrimp shell powder,which could be used as sources of dietary calcium supplement.