Abstract: Cultured tilapia and Litopeneaus vannamei in Guangdong province were selected to study the residues of fishery chemotherapeutic agents, The residues difference between their size were compared and its distribution were analyzed. The result showed that the residues of chloramphenicol, diethylstilbestrol, furazolidone in tilapia were not found. Diethylstilbestrol, furazolidone, chloramphenicol, olaquindox, oxilinic acid were not found in Litopeneaus vannamei, while oxytetracycline, dipterex, sulfamethoxazole, trimethoprim, enrofloxacin all were detected. Quantity of fishery chemotherapeutic agents varied with size and position. Negative correlation exists between body weight and fishery chemotherapeutic agents. Quantity of fishery chemotherapeutic agents in viscera was significant higher than in muscle of tilapia, head was the main position for fishery chemotherapeutic agents residues in Litopeneaus vannamei.