It is pointed that the main reasons of engineering change including the shortcoming of the product,the wrong design,the improvement of the product structure,the change of the customers' requirement,the quality of the product,the condition change of the product,etc.. All the factors and their relations related to engineering change management are analyzed. Such factors as the changing process and the product lifecycle management are discussed in detail. After analyzing the relation between engineering change management and product lifecycle management, the object of engineering change management and its difference is put forward. The basic aim of engineering change management is to develop change ratio of products with lower cost and less error. It is argued that effective product lifecycle management is fundamental to engineering change management. A model of implementation of engineering change management is provided according to the previous analysis.