Abstract:This paper discusses the ecological stoichiometric characteristics of plants, litter and soils of urban green plants. The results were as follows: (1) the order of average contents of C, N and P in green plants from high to low as follows arbors>shrubs> herbs, and the contents of C, N and P in same ornamental plants of different organs was differ, which showed leaf>stem>root. (2) The nitrogen absorptivity was significantly higher than that of phosphorus absorptivity of urban green plants (P<0.01), and the nitrogen and phosphorus absorptivity showed arbors>shrubs> herbs, which the nitrogen absorptivity of arbors, shrubs and herbs had a significant difference (P<0.05) and the phosphorus absorptivity had no significant difference (P>0.05). (3) The contents of C, N and P in litter showed herbs >shrubs> arbors, which the content of P had no significant difference. The contents of C, N and P in soil showed herbs >shrubs> arbors, which the N/P had no significant difference. The contents of C, N and P in soil microbial biomass showed herbs >shrubs> arbors, which the C/N, C/P and N/P had no significant difference. (4) The contents of C, N and P of plants, litter, soils and soil microbial biomass decreased with the increasing of the temperature of the growing season and increased with the increasing of the annual precipitation, which the absolute value of regression coefficient of P was lower than that of C and N. (5) The contents of C and N in plants, litter and soils had a significant positive correlation. The contents of N and P in plants, litter and soils had a significant positive correlation. The C/N and N/P in litter had a significant negative correlation. The C/N and N/P in plants and soils had a significant positive correlation. The C/N and N/P in plants, litter and soils had a significant positive correlation. (6) Canonical correspondence analysis showed that the plant height, crown, stem diameter, specific leaf area and leaf area index had a large effect on the contents of C, N, P and C/N, C/P and N/P of plant, litter, soil and soil microbial biomass. The plant height, crown, stem diameter had a negative correlation with specific leaf area and leaf area index, and had a negative correlation with the contents of C, N, P of litter, soil and soil microbial biomass, and had a positive correlation with the contents of C, N, P of plants, while the contents of C, N, P and C/N, C/P and N/P had a positive correlation in litter, soil and soil microbial biomass. This study provides a scientific guidance for restoration of the urban green plants in China.