Abstract: Constrained minimum vertex cover in bipartite graphs （Min-CVCB）problem is a NP-complete problem, it can＇t be solved in polynomial time, unless P= NP. In this paper, we provide an approximation algor/thm which is based on chain implication to solve this pr

Key words: Constrained minimum vertex cover in bipartite graphs, Approximation algorithm, Parameterized computation,Polynomial time approximation scheme