In order to reveal the reason for low fruit setting rate of a new very precocious loquat line ‘Chuanzao loquat’ in the first florescence,we adopted the method of field experiment to observe flowering stage of ‘Chuanzao loquat’ in the first florescence.Stigma receptivity was measure by benzidine-H₂O₂,pollen vitality was tested by TTC method and pollen tube growth was observed by aniline blue staining method in this study.Results showed that:(1)The first florescence of 'Chuanzao loquat’ to enter beginning bloom stage was mid-July and full bloom stage was from late July to early Aug.The final bloom stage was from mid-Aug.to late Aug.The highest,lowest and average air temperature in the first florescence was 34.9 ℃,18.9 ℃ and 26.03 ℃,respectively.(2) The stigma with receptivity was on 0-4 d after flowering.The stigma with very strong receptivity and pollen with the highest viability was on 1 d after flowering,then the pollen viability rapidly reduced.(3)Pollen tubes had arrived in style base at 48 h and entered the ovule at 96 h after self-pollination,but very few.Accordingly,the combination of many factors such as short duration of stigma strong receptivity,pollen viability decreased rapidly,very few pollen tubes which could arrive at style base and enter the ovule and high temperature was the important reason of low fruit-set rate of ‘Chuanzao loquat’ in the first florescence.