This experiment studied the escapement behavior of black carp (Mylopharyngodon piceus) . The rapid escapement behavior of tested fish triggered by electric shock was analyzed qualitatively, and the acceleration, maximum acceleration and deceleration during sprinting were analyzed quantitatively. The experiment was conducted in natural light condition with water temperature of 20 ± 1 ℃. The tested fish were categorized to 3 groups according to body length: Young fish (9.21 ± 1.89) cm (n=30), Juvenile fish ( 17.83 ± 2.67 ) cm (n=30), Sub-adult fish ( 61.45 ± 0.80 ) cm (n=10). The results showed that the maximum absolute escape speeds of tested fish corresponding to 3 different size groups were 1.261 ± 0.279 m/s, 1.542 ± 0.280 m/s and 2.292 ± 0.567 m/s, the time to reach the highest sprinting speed were (0.249±0.089) s, (0.293±0.067) s and (0.216±0.024) s, the maximum relative escape speeds(Multiple to length to fish swimming distance in per second) were (13.694 ± 3.032) BL/s, (8.648 ± 1.571) BL/s and (3.729 ± 0.923) BL/s. Fish slowed down to coast with the body kept steady (no tail-beat) when test fish reached the best sprinting speed. One-way ANOVA. difference analysis showed that the absolute sprinting speed of tested fish increased as body length increased and Sub-adult fish (61.45±0.80 cm) had a faster absolute sprinting speed than Young fish (9.21±1.89 cm) (P < 0.05) (Fig.2); while the relative sprinting speed of tested fish decreased as the body length increased, presenting significant difference in the maximum relative sprinting speed among the 3 tested groups (P < 0.05)(Fig.4); the value of absolute coast deceleration of the Sub-adult fish significantly higher than that of the Young fish and Juvenile fish (17.83±2.67 cm) (P < 0.05) (Fig.5); there is no significant difference in the relative coast acceleration among the 3 tested groups (P>0.05) (Fig.5).