Abstract: 【Objective】To analyze genetic diversity of ISSR molecular markers and agronomic traits of Pleurotus citrinopileatus germplasms,which could provide reference for the breeding and genetic improvement of P. citrinopileatus varieties resistant to high temperature in Guangxi. 【Method】Detection of ISSR molecular maker,identification of phenotypic traits and heat resistance of P. citrinopileatus germplasms was carried out to analyze genetic diversity with 29 strains of P. citrinopileatus as materials,included cluster analysis,correlation analysis and principal component analysis,so as to screen high-quality P. citrinopileatus germplasm resources resistant to high temperature. 【Result】The cluster analysis of 29 strains of P. citrinopilestus using 16 ISSR primers showed that the genetic similarity coefficient between the tested strains ranged from 0.67 to 0.96. When the genetic similarity coefficient was 0.79, the strains could be divided into 14 groups, of which 9 were distributed in Guangxi, including 3 wild germplasm groups. These results indicated that there were great genetic differences and rich genetic background in P. citrinopilestus germplasms.The Shannon-wiener diversity index（H’） of quantitative traits of the remaining 26 strains were 0.516-2.010 after removing the strains not fruiting and with the same phenotypic traits, among which H’ in the pileus diameter was the highest, and H’ in the survival rate of bacteria sticks was the lowest. They were divided into 7 groups based on phenotypic traits, among which 6 groups were distributed in Guangxi. The groupⅠhad large number and small size of fruiting body per cluster, which could be used for ornamental purposes. The group Ⅱ was the varieties outside Guangxi, the number of fruiting body per cluster was large, and the yield of the first flush was high, which could be used as the improvement of the number of fruiting bodies and the yield of the first flush. Group Ⅲ was Guangxi varieties with a few number of fruiting body per cluster,could be applied to improve number of fruiting body; group Ⅳ was also Guangxi varieties with bigger pileus size,which could be applied to improve pileus size; group Ⅴ with deep pileus color and high ratio of pileus diameter to stipe length,could be applied to improve pileus color and mushroom shape; group Ⅵ belonged to main Guangxi commercial varieties with great comprehensive agronomic properties and early maturity,and could be used as parent material for early maturity and commodity character improvement; group Ⅶ was Guangxi wild germplasm with deep scales color of primary sporophore pileus and high total yield, which could be applied to improve scales color and higher production. The correlation analysis showed that extremely significant correlation（P＜0.01, the same below） with 28 pairs of traits and significant correlation（P＜0.05） with 21 pairs of traits existed among the 22 agronomic traits,among which extremely significant positive correlation or extremely significant negative correlation （|r|＞0.800） was between first flush yield and number of fruiting body per cluster,stipe length and ratio of pileus diameter to stipe length respectively,and extremely significant negative correlation（r=-0.636） was between harvest time and total yield. The principal component analysis showed that the cumulative contribution rate of the 7 principal components was 83.117%. The results of heat resistance test showed that, 9 strains of heat resistant type,12 strains of intermediate type and 5 strains of heat labile type were identified from 26 germplasms with clear genetic relationship and normal fruiting,all kinds of materials were distributed in Guangxi. 【Conclusion】The local germplasm resources of P. citrinopilestus in Guangxi have rich genetic diversity and great breeding potential. The number of fruiting bodies per cluster can be improved as first flush yield trait,harvest time can be screened as total yield trait and the stipe length as ratio of pileus diameter to stipe length trait.