In order to study the stability of winner-loser effect of dominant and subordinate crayfish Procambarus clakii, and discuss the agonistic strategy when they face new opponent in the same size, we first put two individual of crayfish marked with different colors together for 3 days and recorded the winner and loser for each pair. We separated the pair for 3 h, then provided a new crayfish for both of them to made two new pairs for 30 min and taped the fighting results for both winners and losers. Among the 40 winners, 23 individuals won the fight with the new crayfish at first time they encountered and the rest was loser. There was no any difference between percent of winner and loser for the dominant crayfish; for the subordinate group, 18 out of 40 won the first fight, no difference between the percent of winner and loser (α ≤ 0.05, Table 1). The level of significance under which the null hypothesis was rejected is α 0.05. We found that (Table 1): 23/40 the origin social status of the crayfish cannot be recognized by the stranger. In the second fight, 18 out of 23 crayfish who won the first game were the winner in the dominant group, the individuals won twice was significant more than that won the first game and lose the second fight. While in the subordinate group, only 11/18 of them won again. In contrast, 13 out of 17 losers for the dominant group and 17 out of 22 losers for the subordinate for the subordinate group lose again in the second fight. No matter crayfish whether dominant nor the subordinate, the number of crayfish who lose twice were significant more than that lose in the first encounter and won the second. That suggested the winner effect was stable for dominant crayfish, while the loser effect is stable for subordinate one. However winner effect is not stable in subordinate crayfish. In addition, we used t-test to analyze the times of fighting, duration of fighting, and dominant index (Table 2﹣5) and found out that the agonistic strategy between the dominant crayfish (no mater they were winner or loser) and subordinate ones was difference that would cause different result of the fight.