Abstract: A new genetic algorithm based on N-decimal system parted coding operator is presented.The codingoperator expresses the genes with N-decimal system floating numbers,and then the genes are divided into integer part and decimal part.The two parts are encoded into chromosomes respectively.The corresponding selection,crossover and mutation operators are designed with the theory of symbol encoding and the properties of N-decimal system floating numbers.In the early stage of the genetic algorithms,the three genetic mechanisms are used both in integer part and decimal part,so that the genetic algorithms have stronger global search ability,keep the population diversity efficiently and avoid falling into local extremum.In the later stage of the genetic algorithms,the three genetic operators are used in decimal part,so the genetic algorithms have stronger local search ability and fast convergence ability.Theoretical analysis shows that the N-decimal system parted coding mechanism is more efficient than the floating encoding method and the binary encoding method.Simulations on some representative functions are given to validate the results and theory.