The charge plan plays an important role in compiling the production plan for steelmaking,and an optimized charge plan will have a far-reaching effect on the stability and efficiency of a steelmaking workshop.According to the characteristics of billet continuous casting process,a new charge plan model is developed by taking into account three constraints:steel grades,dimensions,and due dates.By using this model,we reduce the production cost by optimizing the sequencing of the contracts.The problem is combinatorial in nature;the complete enumeration of all its possibilities is computationally prohibitive.Therefore,a modified partheno-genetic algorithm(PGA) is employed to search optimum/near-optimum solutions.During the solving process,reasonable algorithm parameters are acquired through the analysis and comparison of different relative parameters.Furthermore,a comparative analysis of the results obtained by implementing the genetic algorithm(GA),PGA and modified PGA on the proposed model reveals that modified PGA outperforms GA or PGA in solving the charge planning problem.