The purpose of this study is to identify the effects of two trunk stability exercise types on the gait factors of stroke patients. We randomly divided 24 old elderly patients with hemiplegia, who were hospitalized due to stroke, into a two groups, each with its own six-week exercise program: one that used of a dynamic trunk stability exercise using with physio-balls(n=12) and a group of one that used a static trunk stability exercise using on mats(n=12). After measuring the participants gait ability a sin a pre-test, we again measured their ability again as in a posttest after two-for both types of six-week exercise programs for each group. The analysis of the data analysis showed that both ball and mat exercise programs significantly improved the participants’ gait velocity and stride length; cadence, however, was significantly changed only by the ball exercise program. In conclusion, both types of trunk stability exercise may be useful in improving the gait ability of stroke patients, and, in particular, the former can be used as an exercise method that effectively significantly affects more various other gait factors.