Ecological effect and integral fuctions of the urban greenbelt depend mainly on rational selection and layout of the landscape plant. The comprehensive evaluation to the quality of the landscape plant can supply the scientific basis for layout of the landscape plant of the urban greenbelt. The paper confirms seven evaluation indexes which are ecological adaptability, ornamental effect, ecological benefit, sanitarian function, resistance to plant diseases and pests, anti-pollution and economic benefit, and based on grey interrelated theory, estabishes graduation and grey comprehensive evaluatio...