The purpose of this study was to examine the differences of exercise demotivation according to personal particulars(gender, age, stages of exercise behavior change) and verify the impacts of exercise demotivation on stages of exercise behavior change. 330 middle-aged exercisers completed questionnaires and 309 data obtained from them were analyzed by one-way MANOVA and discrminant analysis. The results of one-way MANOVA revealed that there was no significant differences of exercise demotivation between the gender, but 3 subscales(reduced exercise enjoyment, reduced exercise drive and time restriction) of exercise demotivation were significantly different according to the age. And 2 subscales(reduced exercise enjoyment, time restriction)were significantly different according to the stages of exercise behavior change. Moreover, the result of discriminant analysis showed that 1 subscale(time restriction) of exercise demotivation discriminated the stages of exercise behavior change significantly.