The paper is performed to evaluate the impact of employee relationship management to maximum productivity of the employees – the case of the small and medium enterprises in Tra Vinh province. The primary data was collected by interviewing 200 employees at 96 companies through the questionnaires. There are some methods using in this research including descriptive statistics, Cronbach's Alpha; Exploratory factors analysis; multivariate linear regression. The results show that the physical, mental, monitor elements, employee’s characteristics, and motivation elements have a positive impact on the maximum productivity of employees. The physical and mental elements of employee relationship management are the most powerful impact factors to maximum productivity of the employees. The results show that beside three elements of employee relationship management is inherited from the literature review; there are two new factors named employee’s characteristics, and motivation elements that also have a positive impact on the maximum productivity of employees. The paper proposes some recommendations to improve the maximum productivity of employees. The paper contributes more evidences to supports the employee relationship management theory and suggest the new research idea in the case of Vietnam.