Abstract: The operations on matrix for both minimax and global-minimum assignment problems of square matrix are applied to those of nonsquare matrix,namely,in the same efficiency with the operations on matrix,both the minimax and global-minimum assignment problems where number of people is unequal to number of tasks are solved.Supposed m >n,the quantity of logical operations to solve the assignment problem of m×n nonsquare matrix with the selection algorithm of precedence rows in this paper is not bigger than O(mn²).The efficiency of selection algorithm of precedence rows is usually comparable to that of operations on matrix in one covering circle.