The objectives of this study was to find the effects of the stability and mobility on the weight distribution and the function of upper limbs. The subjects o f this study were 18 hemiplegic patient who either hospitalized in or out patients at the Rehabilitation hospital, Younsei University College of Medicine. The study on these patient were done from Jan. 20, 1999 through Feb. 9, 1999. 1 . The effects of trunk and pelvis therapeutic exercise on the weight distribution measured and analyzed by Limb Loader, before and after the treatment.2. We compared the functional reach test(FRT) value in standing position, before and after the treatment. We also studied the effects of reach out position on the weight distribution. 3. To compare the standing control ability, we did arm raise tasks(ARAT) and arm reach tasks(ARET) before and after the treatment. The data were analyzed by SPSS and paired t-test. The findings were as follows: 1. Subjects bore more weight 25.33kg to 28.94kg on the affected leg. 2. FRT increased from 14.96cm to 17.63cm though, no significant change of weight distribution showed at reach out position. 3 . Arm raise tasks(ARAT) and arm reach tasks(ARET) each increased from 40.61, 26.72 to 42.94, 30.39. In conclusion, this study showed significant efects o f the stability and the mobility of trunk and pelvis on the symmetric weight distribution and the standing balance improvement.