Abstract: The principles and methods of design of a seriation centrifugal compressors have been systematically discussed in this paper. First of all, various problems, such as the design feature　of a seriation centrifugal compressors, chock and surge, match between impellers and diffusers,　osses and criteria of the optimal distribution of velocities etc: have been analysed according to　aerodynamics of turbomachinary. On this basis, a concrete method of design has been proposed. It comprises the subjects, such　as the scheme of distributing grade of impellers and diffusers, the choise of basic aerodynamical　and mechanical parameters, the calculation of S1, and S2 steam surfaces, the methods of shaping inducers, etc.　Seriation centrifugal compressors of type CZ-355 which have been designed in accordance with　above principles has successfully reached the design indexes, and have been appraised and put　into operation. The main part of the experiment results was also presented in this paper.