Objective To observe the effect of iron fortified soy sauce on improving the physical ability of students. Methods Boy students suffering from iron deficiency anemia and eating in a school canteen were selected as IDA group and fed with iron fortified soy sauce for 10 months. Other boy students without anemia and not eating in school were regarded as NA group and having common soy sauce. Hb, SF, sTfR, SI, maximum oxygen consumption, 24 h heart rate monitoring and energy consumption of normal students (NA) and anemic students (IDA) were measured before and after the trial. Results Hb, SF, sTfR and SI of IDA subjects were improved significantly after the intervention with iron fortified soy sauce (P＜0.01). There was no change of these indexes in NA subjects before and after the trial. In addition, the increase of VO_2max/FFM, WT_max, NetHRL, AAT and EE in IDA subjects was (9.74±2.88 )ml/(kg?min), (3.11±0.88) min, (8.55±5.11)beats/min, (5.28±2.04 )min and (386±108) kJ/d, respectively, which were significantly different from the change of relative indexes in NA subjects (P＜0.01). Conclusion Iron fortified soy sauce was effective in reducing iron deficiency anemia and significantly improving the aerobic ability of IDA students. The intensity and the time period of aerobic activity during leisure time was also strengthened significantly in IDA subjects after intervention with iron fortified soy sauce.