Abstract:By using Li-6400 portable photosynthesis system,the photosynthetic character of 80 apricot,plum and apricot plum varieties were measured.The result showed that difference among the tested genotypes were extreme significant.According to photosynthesis rate(Pn),80 genotypes were classified into highest,middle and lowest photosynthesis type by using cluster analysis.Highest,higher,middle and lowest water using efficiency(WUE) type were also ranked according to WUE.Distribution frequency of the highest photosynthesis rate type varieties in apricot was higher than that in plum and apricot plum,account for 50.0%.Frequency of middle photosynthesis rate type in plum and apricot plum,accounted for 55.2% and 62.5% respectively.There were more higher and middle WUE genotypes in apricot and apricot plum,but distribution of WUE types in plum was broad.2 plum genotypes 'Aodeluoda','Lichadezaosheng' and 3 apricot genotypes 'Chaoren','Lanzhoudajiexing','Yangshaoxing'with highest Pn.and higher WUE were choosed for useing in breeding.