Seasonal variations in rigor morns of several cultured freshwaterfish, bighead, silver carp and grass carp, were studied in this paper. The experimental results showed that the variations were markedly evident. These threespecies of fish stored at 0℃ reached full rigor state after 2 to 16 hrs (mostly 6 to10 hrs) in May to July and in October, but in the months from January to Marchafter 50 to 100 hrs (about 2to 4 days). However,in the months of April and November, the time after death to full rigor beginning were 10 to 60 hrs. It was foundthat a good negative correlation existed between the seasonal temperature of pondwater and the duration of full rigor. The correlation coefficient was - 0.9236 (P0.01). This correlationship showed that the duration of rigor morns was dependent on the temperature of pond water where the fish cultured. Rigor mornsalso varied with different physiological states before death. The duration of rigormorns of bighead killed alive was much longer than that of fish dead after struggling. The difference of the duration of rigor morns between the species of fishwas not so evident. Therefore, besides distributing of live fish a new distributionway of cultured freshwater fish was suggested,namely the fish killed alive mightbe handled and distributed with ice or without ice stored if the seasonal temperature was less than 10℃,and within a longer time than that for distributing of livefish. The quality criteria and freshness index for freshwater fish were also discussed in the paper.