The importance of continuous learning for achieving sales success in ever-changing competitive environment is increasingly being recognized. In the present study, we hypothesized that the positive relationship between conscientiousness and sales performance, which had already been recognized in several literatures, would be mediated by continuous learning. We tested the hypothesis by the structural equation model with latent variable using the data gathered from the 139 sales representatives working for a large Japanese information system company listed on the Tokyo Stock Exchange, Part I. We found that conscientiousness significantly affected on continuous learning, but that continuous learning did not significantly influence sales performance. These findings indicated that our hypothesis was not supported by the data. We also found that openness to experience and the degree of the sales representative's perception of competitiveness in the market environment were positively correlated with continuous learning. We discuss implications of the study and give suggestions for future research.