This study focuses on the relationships among locus of control, job satisfaction, and demographic variables for salespeople. We use one-way ANOV A, t-test, Pearson product-moment correlation analysis, consistency analysis, and stepwise regression analysis to analyze data. The results indicate that (I) for the variables of age, marriage, monthly income, position, and in-out work, statistically significant differences on locus of control for salespeople are found, (2) for the variables of sex, monthly income, position, and in-out work, statistically significant differences on whole job satisfaction for salespeople are found, (3) the relationships between locus of control and each factor in job satisfaction are significantly negative correlation, i.e., more internal locus of control, more job satisfaction, (4) salary satisfaction and promotion satisfaction are the lowest level of satisfaction for salespeople, and (5) locus of control and demographic variables can predict the variance of job satisfaction by 26.20%.