Abstract:Utilization of Erianthus arundinaceus is a hot topic in modern sugarcane germplasm innovation program. Sugarcane breeders expect to permeate excellent characteristics of Erianthus arundinaceus into Saccharum through intergeneric cross. The F1 hybrids perform a base and importance role in studying and utilization of Erianthus arundinaceus. In this study, chromosomes of F1 hybrids between Saccharum officinarum and Erianthus arundinaceus were studied by genomic in situ hybridization (GISH) to discover chromosome genetic behavior of F1 hybrids. The results of GISH revealed that F1 hybrids chromosome showed a total of 68 to 70 chromosomes, of which 40 were derived from Badila （Saccharum officinarum） and 28 to 30 were derived from Hainan Erianthus arundinaceus. Chromosome translocation and exchange were not found. Most of chromosomes belong to median centromere type （m） and few of chromosomes belong to submetacentromere type (sm) in 5 F1 clones, the karyotype is 1B or 2B. The results revealed that 5 F1 clones were product of n n transmission. These results may serve as chromosome genetic basis of the hybrid progeny for utilization of Erianthus arundinaceus germplasm in sugarcane breeding program.