A construction project could not be finished without a number of human resources who supported the process of construction itself. To be motivated and productive, workers needed to have great interest, and to get satisfaction from the job. This research was aimed at knowing the impact of work motivation on the project finishing time. Motivation played major role in a group of people who worked together in order to achieve the organization’s goal. The data were gotten through questionnaire as the primary data and some observations to the workers of PT. Sambas Wijaya Purbalingga. The technique to analyze data was by using double linier regression analysis. The result of the data analysis showed that the free variables which included X1-X6 man’s need (X1) , compensation (X2), communication (X3), training (X4), leadership (X5), as well as achievement and work environment (X6) simultaneously and partially had a positive impact on the project finishing time. The equation was Y = 4.460 + 0.105 X1 + 0.256 X3 + 1.108 X6 with R = 0.560 and std. error 1.20576. The factor affecting the construction project workers’ motivation most in finishing the project was the communication factor ( X1) which was 0.256 %.