Abstract: Using the methods of field sampling and laboratory incubation, the change of microorganism quantity in the root layer soil of three common greenspace plant species irrigated by both clean and recycled water for the shortterm and longterm duration was studied. The results showed that the quantity of bacteria, fungi, actinomycetes in the rhizosphere soil of Duranta repens and Ficus microcarpa decreased as soil depth increased, but the quantity of fungi was the most in 20-40 cm soil layer irrigated by clean water for shortterm. The quantitative distribution of bacteria and fungi in the rhizosphere soil of Zoysia pacifica was similar to that of in the rhizosphere soil of Duranta repens and Ficus microcarpa, but the quantitative distribution of actinomycetes was the most in 20-40 cm soil layer. Compared with clean water irrigation, the quantitative distribution of bacteria, fungi, actinomycetes in the rhizosphere soil of Zoysia pacifica, Duranta repens and Ficus microcarpa that irrigated by recycled water increased evidently, and there were significant differences in the quantity of microorganisms in the 0-20 cm soil layer. The quantitative distribution of the microorganisms in the 20-40 cm and 40-60 cm soil layers varied with different plant species.