In the process of generating assembly dimension chain automatically,there are many problems such as complex assembly relationship,variety of constraints of components and complex dimension and tolerance relations of components.These problems lead to many difficulties in search process and need lots of man-machine interaction.Because of these difficulties,this paper presents a method of automatic generation of assembly dimension chain based on tolerance cell.This method is realized through obtaining assembly tolerance cell and part tolerance cell first.These two types of tolerance cell are extracted and expressed in the form of linked list structure in computer further.Then assembly dimension chain is searched automatically based on obtained tolerance cell,and the correct assembly dimension chain is extracted finally.A system of generating assembly dimension chain automatically has been developed based on DELMIA and successfully deployed in aircraft assembly simulation in the engineering practice. In the process of generating assembly dimension chain automatically, there are many problems such as complex assembly relationship, variety of constraints of components and complex dimension and tolerance relations of components. The problem problems to many difficulties in search process and need lots of man-machine interaction.Because of these difficulties, this paper presents a method of automatic generation of assembly dimension chain based on tolerance cell. This method is realized through obtaining assembly tolerance cell and part tolerance cell first. sese two types of tolerance cell are extracted and expressed in the form of linked list structure in computer further.Then assembly dimension chain is searched automatically based on obtained tolerance cell, and the correct assembly dimension chain is extracted finally.A system of generating assembly dimension chain automatically has been developed based on DELMIA and posted in aircraft assembly simulation in the engineerin g practice.