This study investigated biomechanical effects on the body center of mass(COM) and joint moments of lower extremity as the weight of sided load in walking. Also the present study showed correlation between body center of mass and joint moments. The motion data used as input data for inverse dynamic simulation were measured by the 3D motion analysis system. Eight healthy, college-aged subjects participated in the experiment, and they walked with side loaded carriage which weighs 0, 5, 10 and 15kg, respectively. Human skeletal models were generated and analyzed by using BRG. LifeMOD and SIMM. For inspection about inverse dynamic simulation results, MSCADAMS was used for forward dynamic simulation. As a result, the COM was more inclined to the opposite side of side loaded carriage as the weight increased. In stance phase, the magnitude of ankle plantar-flexion moment increased as the weight of side loaded carriage increased. In knee joint, the knee extension moment of unloading side was smaller than that of loading side when the weight increased. The hip extension moment of loading side was larger than that of unloading side. In the present study, the results showed that the human used the ankle and hip joint of loading side to support the body and the knee joint of unloading side to progress the walking with keeping the balance of the body. This study could be very useful to analyze the various biomechanical effects in other human working.