The seeds of two Festuca arundinace cultivars were radiated by Co⁶⁰-γ rays with 0 Gy, 100 Gy, 200 Gyand 300 Gy radiation doses, and the chromosome number and karyotype of these two cultivars and radiated lineswere investigated by using histological sectioning technique. The results showed that the two varieties possessed thesame chromosome number（2n=42） belonging to macrochromosome but exhibited some differences in the compo-nents of karyotype. The most chromosomes of the two varieties were metacentric and most of the karyotype was sym-metric. The chromosome karyotype of the radiated lines by different doses of radiation showed differences for eachindividual Festuca arundinace cultivar, and chromosome structure changes were also observed in the different linesby the same doses of radiation. After radiation, change of the chromosome number n=40 and n=42 were found in theradiated lines. There were three karyotypes 2B, 2C and 1B found in the lines. Central and near central chromosomeswere mostly found in the composition structure of karyotype and only a few had middle or near the end chromo-somes, very few small chromosome and satellite were detected. Our results provide some information at the chromo-some level for the future germplasm resources research and utilization of the turfgrass.