Changes in construction projects are considered as prevalent phenomenon. Where, most of projects face changes in drawings, specifications, work scope, or contractual conditions. The traditional construction followed in Syrian projects has a long time span between planning, design, and construction. As result the possibility of changes occurrence in any project becomes considerable. There are many causes of change orders in construction industry. These changes, mostly causes time and cost overrun and managerial complications. The objective of this study is determining the main causes of change orders; arranging them according to their significance; and studying their effects on project’s cost and time. The owner or the engineer supervising the project is the party who is responsible for change orders in the project.