Abstract: The combination capabilities of three types of discrete recombination operators‚one point crossover‚multiple point crossover and uniform crossover operators in real coded genetic algorithms are analyzed with combinatorics．The combination capability of the operators is measured by the number of different chromosomes produced by the operators．It is shown that operating on the same pair of parent chromosomes‚one point crossover can produced at most 2（ n－1） different chromosomes‚multiple point crossover2C k n－1‚and uniform crossover2（2n－1－1）．Function optimization experiments show that which operator works better in an algorithm depends on both the combination capability of the operator and the problem to be optimized．

Key words: genetic algorithm, real coding, discrete recombination operator