The original focus of this study was to investigate the immediate effects of lumbar rotational mobilization on the one-legged standing ability. Fifteen subjects (6 men and 9 women, mean age = 22.77 (SD = 1.21), mean height = 165.46cm (SD = 11.65), mean weight = 61.46kg (SD = 8.29) volunteers from healthy individuals were recruited and randomized to a lumbar rotational mobilization (LRM) group and a trunk rotational exercise (TRE) group. Mobilization (grade 3 or 4) was applied to the LRM group on the lumbar spine (L1 to L5) in a side-lying, and trunk twist exercise (left and right side) was applied the to the TRE group with lunge position. Center of pressure (COP) and the velocity of the center of pressure (VCOP) of each participant were measured as a balance ability through one leg standing position. Results are as follows. In within-group difference, the COP of the LRM group reduced during standing with the right foot, but the VCOP change of the LRM was not statistically significant. In between-groups difference, COP of TRE group was decreased compared with LRM group only during left leg standing in the eyes (p <.05). The results of this study suggest that LRM is more effective than TRE in improving balance ability.