A construction industry is one of the most important sector components, and the success of any construction project depends primarily on the effectiveness of the engineering management for all activities related to this project (i.e., from the project starting date till its finishing date). Several investigations indicated that various factors affecting the construction management; therefore, determining these factors and designing a control system to them could show a huge difference in the project's productivity, as well as labor productivity. The field study for this research included a designed questionnaire sheet, then evaluate obtained data using SPSS program. Considering the results of the practical part of this research, several findings were obtained, such as, the survey showed that the most affecting factors on the basic time are , Awaiting for materials (outside delivery) , Fatigue , Lack of access , etc. There is an agreement that labor productivity measurement is important to improve labor work performance on construction sites and that labor productivity has the most impact on work performance. XV The research indicated twelve factors affecting labor productivity; however, the most of these are: lack of availability of skilled workers, accuracy of the estimates, weather conditions, inadequate supervision, inadequate supplies and changes order, therefore it is recommended that the project manager should pay attention to those factors in order to obtain the desired productivity.