Abstract: The plant pollen which is conservative and stable on genetic has great significance for the study on plant classification, origin and evolution. Optical microscopy and scanning electron microscope(SEM) were used to compare the pollen grains of nine kinds of Potentilla species in Daqing area. The pollen grains shows many similarity through optical microscopy and 4000×scanning electron microscope. Through 8000×scanning electron microscope, it was showed three types of surface strip decoration of non-double-edge ridge ornamentation, multi - groove ridge strip motif and non-groove strip，the width of ridge is from 0.11μm to 0.29μm and the width between ridges is from 0.37μm to 0.78μm,continuously or discontinuously ridges. There were holes or microparticle on the surface and the colporate shapes were linear and fractured. The evolution trend concluded by the 9 kinds of Potentilla species pollen study of system evolution and classification was consistent with the traditional classification trend.