Abstract: Here introduced are a series of algorithms for building dimension chain and dimension loop based on the comprehension of graph and the model of dimension chain and dimension loop. By identifying dimension and other graph object, the algorithms can build the constraint relationship among dimension and entity,dimension and dimension, and entity and entity. Finally, a dimension driven parameter design algorithm is given based on the dimension chain and dimension loop. The algorithms can achieve the variation of entity based on the modification of dimension, as well as keep geometry and topology relationship among graph entity and dimension constraint.