In this study,the F₁ generation from wild Miscanthus lutarioriparia×Miscanthus sinensis hybridization was used to induce tetraploid and then characterize the morphology,cytology.and physiological property.The results obtained from the experiment showed that:(1)The polyploid plants were produced through treatment in medium or solution supplemented with different concentrations of colchicine.The induction frequency of tetraploid plants was 8.7% by using the embryogenic callus as material under the treatment of soaking in solution containing 0.2%(W/V) colchicine for 48 h,and the rate of tetraploid plants induced from bud was 10.6% on the treatment medium with colchicine 0.05%(W/V) for 15 d;The rate of tetraploid reached 11.1% from seedling with 0.1%(W/V) colchicine treatment on the medium for 10 d.(2)The chromosome identification showed that the chromosome number of polyploid is 2n=4x=76,and the wild type plant is 2n=2x=38.(3)The polyploid showed better heterobeltiosis under normal growth conditions with higher plant height,thicker shoot and bigger leaves compared to parents.