The salesperson interacts with customers in place of corporations and enhances perceived service levels of customer. For this reason, the salesperson plays a pivotal role in business performance. We aim to examine the effects of social capital and human capital investment on role stresses, work engagement and sales effort based on the JD-R model. As a form of job resources, social capital and human capital investment were proposed as leading factors of salesperson’s sales efforts through work engagement. Role overload and role ambiguity were suggested as the job demands, reducing work engagement of salespersons. We also analyzed the effects of social capital and human capital investment on role overload and role ambiguity. In this study, we collected data from 691 salespeople in South Korea. Data analysis was performed using structural equation modeling. The results showed that social capital has a positive influence on work engagement and negative influence on role stresses(role overload and role ambiguity). Human capital investment has a positive effect on work engagement, but human capital investment is not significant on role stresses. Role ambiguity reduces work engagement. Finally, we found that work engagement of salesperson enhances sales effort. These results represent that social capital and human capital investment can be regarded as the job resources for salesperson.