The aim of this study was to investigate the fertility and its cytological mechanism in triploid grape ‘Summer Black’.The meiosis of pollen mother cells (PMCs) and gamete fertility in triploid grape 'Summer Black' were studied by cytogenetic methods.Results showed that:(1)numerous meiotic abnormalities,including precocious migration of chromosomes to the poles,lagging chromosomes,chromosome bridges,asymmetrical separation and micronuclei were found during the meiosis process.The frequency of asymmetrical separation (65.68%) was the highest in all of the meiotic abnormalities.(2)The pollen germination rate of this triploid grape was 1.65%,and its pollen sizes ranged from 18.0-50.0 μm with a bimodal frequency distribution.(3)Hybrid seedlings were obtained from crossing between ‘Summer Black’ and tetraploid varieties,which indicated some gametes were fertile in ‘Summer Black’.It was indicated that abnormal meiosis of PMCs was the cytogenetic reason for fertility reduction of triploid grape.While a little bit fertile unreduced pollens was produced by the abnormal meiosis.It was proved that the breeding application of this triploid grape was possible.