Waste resulting from construction operations affect the project, so that it adds financial values of the project, without leading to any improvement in it,or to improve the functional capabilities of the project, and lead to increased quantities required, thereby increasing the cost of the project and the accumulation of environmentally harmful solid waste. In this research, We will discuss the most important factors affecting the increase waste in the Syrian construction projects by identifying the most important causess that lead to an increase in waste materials, as well as identify the most important causes that lead to increased waste associated with design, storage or supervision. These factors will be arranged to determine the most effective on the project. At the end of the research we will formulated mathematical model to Optimize cutting of reinforced steel bars and Lindo program will be used to solve this model. It has been shown by the study that a large proportion of waste is resulting from random cutting bars.