Purpose: The purpose of this study is to compare of pelvis movements according to type and weight change of the bag during the descent of the stairs. Methods: The experiment was performed on 10 university students. The bag type was backpack, shoulder bag, and the weight was 3 ㎏ and 5 ㎏. Subjects were randomly assigned to four conditions. Five measurements were made for each condition, with a one minute break. A wireless 3-axis accelerometer(Delsys, USA) was used to measure pelvic motion during the descent of the stairs. The left and right movement of the pelvis was measured by setting the x-axis, the front and back movement of the pelvis as y-axis, and the pelvis movement as the z-axis. Repeated measurement variance analysis was used to determine the difference in type and weight change of the bag. Scheffe was used for the post test to determine the difference of the four conditions. Statistical significance level (a = .05) was set and statistical analysis of data was performed using SPSS 18.0. Results: In the measurement of pelvic movement, there was a significant difference in the x-axis according to the type and weight change of the bag. There was no significant difference in the y and z axis according to the weight change of the bag, but there was a significant difference in type of the bag. Conclusion: When carrying the bag and descent of the stairs, it is effective to use a light weight backpack to improve the stability of the trunk and prevent musculoskeletal diseases.