Abstract:Using microclimatic dada recorded from 2002 to 2003 in litchi （Litchi chinensis） forest in Huadu, the relationship between the microclimate and macroclimate was studied. The results indicated that average monthly air temperature in litchi forest canopy was lower by 0.35-0.75℃ than that obtained at meteorological station in Huadu. This was particularly obvious in winter and spring, and at night. Temperature in the canopy was by 0.2-0.4℃ higher than that above the canopy, which was more obvious in summer and autumn and in the daytime. Average monthly relative humidity in litchi forest increased by 7% compared to that in macroclimate, indicating that the humidification in litchi forest always causes diseases and pests.