According to the video records of spatial distribution of individuals in the fish school taken in the lab, the distances among individuals in fish school measured and calculated by the body centroid method (BCM), segment method (SM) and broken line of three point method (BLM) indicate that the most of distances are varied in the range of 0.5-2 times body length (BL) while the number of individuals increasing to a certain level. The results by SM were basically same as the one from BLM, and the precision of BCM was lower than the others. When the body length was greater than 0.2 BL, the frequency of distance appearance of BLM was generally higher than SM’s and its result was more precise. And the distances calculated by means of the SM and BLM were mostly allocated in the range of 0.6-0.8 BL, which revealed that the range might be the preferred distance of the fish