We observed the behaviors including hiding in gaps and swimming layers of yellow catfish larvae and juveniles under laboratory condition.The results showed that the 118dayold larvae preferred hiding in gaps,but 1925 days old juveniles did not select gaps.The 118 days old larvae significantly preferred hiding in gaps during the day than at night.The 27 days old larvae significantly preferred hiding in 0.3 cm gaps than in 0.5 cm gaps,and the 918 days old larvae only selected a wide (0.5 cm) gap.Before 18 d,the percentage of larvae preferring the bottom gap (20 cm above the bottom) was significantly higher than that preferring surface gap (20 cm below the surface) during the day.At night,the percentage of 1318 days old larvae preferring the bottom gap (20 cm above the bottom) was not significant different from that preferring surface gap (20 cm below the surface).The 310 days old larvae and 2132 days old juveniles preferred habitat in bottom water (less than 20cm from the bottom),and 1120 days old juveniles showed a fluctuation preference in different water layers.The results could help to improve yellow catfish fry rearing methods and increase the survival rate of fry rearing.