Abstract: Many synthesis problems of chemical processes are attributed to combinatorial optimization problems which are diffcult to solve. Line-up Competition Algorithm (LCA) presented in part Ⅰ is applied to the structural and parameter optimization for process synthesis in this paper. The expression of competition driving force and the algorithmic framework are given for solving combinatorial optimization problems. The wto principles of determining mutation adjacent regions are proposed which are helpful to balance local search and global search. The algorithm is applied to the optimization of a large scale pressure relief header network and a heat exchanger network synthesis problem,respectively, and the results show that LCA algorithm can discover a very good near-optimum solution after examining an extremely small fraction of possible solutions. The solution is superior to those obtained with simulated annealing algorithms and genetic algorithms in literature. Examples demonstrate that LCA algorithm has great potential for solving combinatorial optimization problems.