Introduction: This research aimed to analyze the effect of 12 weeks aerobic exercise training on some

characteristics of immune system and general health of women with breast cancer. Methods: 40 female

with breast cancer, undertaking chemotherapy, were classified in exercise group with mean age of 36/9±13/2

years, weight of 67/2±9/95 kilograms and body mass index of 21/9±2/9 kg/m2 and control group with mean

age of 38/6±10/1 years, weight of 65/1±8/28 kilograms and body mass index of 21/4±2/1kg/m2. Exercise

group Perfored in 12 contionous weeks walking with moderate intensity (based on Modified-Borg scale and

40-60% Maximum Heart rate)/3 times a week/30-45 minutes in each session. General Health Questionnaire

(GHQ) was used for evaluating general health level. Before and after 4, 8 and 12 weeks CBC DIFF test was

conducted for aim of assessing some characteristics of immune system. CANCOVA was used to determine

the pure effect of exercise intervention. The data were analyzed with significant level of p≤0/05 and by SPSS

16. Results: General health and hope of life was decreased significantly after intervention in control group

(p≤0.05). Number of leukocytes of exercise group was higher after the exercise intervention, but this

difference was not significant, but number of leukocytes of control group was decreased significantly

(p≥0.05). Conclusion: Regular aerobic exercise with moderate intensity is an effective way in maintenance

the number of leukocytes, improving immune system and enhancing levels of general health.