Abstract：In order to improve the microspore culture system in Brassica juncea（L.） Czern. et Coss. and promote its application in breeding and basic research，we used 12 different genotypes of Brassica ica juncea（ L.） Czern. et Coss. as experimental materials to study the effects of genotype，heat shock induction and donor plants growth conditions，especially atmospheric temperature on microspore culture in Brassica juncea（L.） Czern. et Coss．The results indicated that microspores in the late uninucleate stage were prismatoidal and characterized with 3 obvious germinal furrows，which can help
identify the length of buds that contained a large proportion of late-uninucleate-stage microspores．2-3 mm buds were appropriate for microspore culture in Brassica juncea（L.）Czern. et Coss．35 °C heat shock for 3 days contributed to the induction of microspore embryogenesis. Genotype was the key factor
that affected the results of microspore culture in Brassica juncea（L.）Czern. et Coss．The ability of embryo yield was quite different among 12 different genotypes．Nine of them produced embryos，V03B0097 and A12959 gave the highest among the 12 genotypes：5.87 and 5.54 embryos per bud，respectively．Low temperature for donor plants growing was appropriate for embryogenesis of microspore culture in Brassica juncea（L.）Czern. et Coss.
