Abstract: Ca2+-ATPase stability of some fresh-water fishes was discussed here, together with study of changes of Ca2+-ATPase and pH when stored at different temperatures. The result showed that the activity of Ca2+-ATPase was decreased with increasing of temperature during treatment, where as 20℃ was the critical point for Ca2+-ATPase activity decrease. Activity of Ca2+-ATPase was preserved very well in the condition pH 7.0 Low temperature was advantageous to maintain Ca2+-ATPase stability. So before processing, fish should be stored in low temperature to get better quality.

Key words: Ca2+-ATPase activity, stability, pH