Abstract: The characters of pollen grains from 20 apricots representing Prunus armeniaca L.，P. sibirica L. and kernel-using apricots of subgenus Armeniaca were investigated with scanning electron microscopy（SEM）cluster analysis，using average linkage means，was then conducted with 10 quantitative and 2 qualitative traits from palynological data. The results showed that all pollen grains of subgenus Armeniaca were monads，isopolar，radially symmetrical，triangular or obtuse-triangular in the polar views，elliptical in the equatorial views，and the pollen was tri-colporate，which was consisted of an ecto-porus and a colpus，the ecto-porus obviously convex，elliptic，covered with irregular reticulate-like pattern and independent of the exine，the colpus usually elongated，entending nearly to the two poles. Pollen with striate ornamentation，presence or absence for perforation，four appurtenance types on the exine surface，such as turnup-like，ridge-like，granular and verrucate，and it is suggested that the between different apricot accessions could be used as important indicator for classification and phylogenetic relationships analysis in this subgenus. Both cluster and principal coordinate analysis classed 20 apricots into three groups：Kernel-using apricots group，mixed group of P. sibirica and P. armeniaca and mixed group of P. armeniaca and kernel-using apricots. The present study suggested that the most kernel-using apricots originated from the natural hybrid of P. armeniaca and P. sibirica，some may also be directly originated from sweet kernel type of P. armeniaca. Moreover，P. sibirica should be more evolutionary than P. armeniaca.

Key words: kernel-using apricots, Prunus armeniaca, P. sibirica, palynology, relationship, origin