[Objective] The aim was to indentify haploid and diploid yeast.[Method] The characteristics of haploid and diploid yeast and their relation were analyzed firstly,and then haploid and diploid yeast were indentified through the methylene blue staining,safranine staining of ascospore and special low temperature treatment test.[Result] After methylene blue staining,the differences of haploid and diploid yeast in activity and size could be observed clearly;the ascospores of diploid strains after sporulating became red after safranine staining,and diploid thalluses were blue,while there were only blue thalluses for haploid strains;after special low temperature treatment,the colony of diploid was obviously larger than that of haploid on the plate.[Conclusion] Haploid and diploid yeast had great differences in morphology,heredity and physiology and could be identified well by means of aided test.
