It is significant for understanding the behavior of chromosome in Saccharum officinarum ? Erianthus rockii F1 hybrids, because it can provide cytology evidence for utilization the wild Erianthus rockii resource. In this paper, the Saccharum officinarum ? Erianthus rockii F1 hybrids and their male parent were used for materials, the meiosis of pollen mother cells were prepared by use squash technique and then were observed under a microscope, the result showed that division of the male parent yunnan95-19 was normal, but in F1 hybrids some abnormal behavior were observed; the further research was proceed by used the GISH technology, and the result indicated that Erianthus rockii has a distance relationship from Saccharum officinarum genus, because in the pollen mother cells of F1 hybrids the chromosome from these two genus could not pairing in meiosis, we detected 15 chromosomes which from Erianthus rockii were formed 15 univalent respectively, further more, the meiosis were observed with lagging chromosomes, elimination chromosomes and disequilibrium separated chromosomes in pollen mother cells of the F1 hybrids, the abnormal division we observed in this paper may illustrate why the pollen were abortive completely in F1 hybrids.