Abstract: A hybrid genetic algorithm,which combined the simple genetic algorithm with the heuristic greedy algorithm,has been presented in this paper.This hybrid genetic algorithm has been applied to Knapsack problem.The calculating results of a Knapsack problem which consists of 50 objects,have shown that this hybrid genetic algorithm is efficient for large scale Knapsack problem.As compared with simple genetic algorithm and greedy algorithm,the quality of results and the performance of this hybrid genetic algorithm have been effectively improved.