Objective To observe the balance beam exercise on psychological behavior of neonatal rats. Methods A total of 32 newborn rats were randomly divided into control group (n=16) and exercise group (n=16).The neonatal rats of the exercise group were trained by balancing for four weeks.And the rats of 36~37 day-old underwent a psychological behavior measurement by animal behaviour platform (open-field test). Results 1) The time of acting in the central area of exercise group [(1.441±0.946) min] was shorter than that of control group [(2.237±0.724) min,t=2.673,P<0.05].2)The distance of acting in the central area of exercise group [(326.633±106.218) cm] was less than that of control group [(427.116±102.185) cm,t=2.727,P<0.05].3) The time of acting in the surrounding area of exercise group [(8.559±0.946) min] was longer than that of control group [(7.735±0.721) min,t=3.226,P<0.01].4)The distance of acting in the surrounding area of exercise group [(1 208.667±176.794) cm] was longer than that of control group [(1 062.900±118.085) cm,t=2.721,P<0.05]. Conclusions Early balance beam exercise increase rats' cognitive ability and emotional stability in the new environment.