Abstract: The study showed that in the Fargesia denudata rhizosphere soil of western Sichuan, the quantity of bacteria and fungi was obviously higher than that in non-rhizosphere soil, while no significant difference was observed for actinomyces, with the average R/S values being 2.36, 2.08 and 1.08, respectively. The activities of acid phosphatases, proteinase, urease, invertase, catalase and polyphenol oxidase in rhizosphere soil were significantly higher than those in non-rhizosphere soil, and their average R/Svalues were respectively 1.48, 1.57, 2.14, 1.37, 1.98 and 1.67. For the F. denudata stands with different ages, the quantity of bacteria and fungi and the activities of test enzymes in rhizosphere soil were in the order of 3-, 5-and 7-year-old stand > 9-, 11-and 13-year-old stand > 1-year-old stand, butno distinct difference was found in the quantity of actinomyces.

Key words: Harmful algal bloom area, Terrestrial input, Al