The purpose of this study was to determine the influence of interpersonal communication on employee motivation at PT. Kereta Api Indonesia (Persero) DAOP IV, Stasiun Besar Semarang Tawang and to determine how much themotivation influence.The methods of collecting data of this research were questionnaires, observation and literature study. The questionnaires were distributed to 45 employees with Proportional Random sampling tecniques. The analysis implemented in this research was simple linear regression analysis. The result of T test for interpersonal communication is 2.734 with significance of 0.009.From the analysis of linear regression in this research, it was found out that the interpersonal communication had positive impact on the employee motivation. Variable that positively influenced the employees job motivation is the interpersonal communication. The result of determination coefficient (R square) was 0.148 or 14.8% of the free variable was interpersonal communication. It meant that 14.8% of the employee motivation was influenced by interpersonal communication. While 85.2% was explained by other variables which were not explored in this research.