Abstract: The transpiration rate has been determined for three tree species by fixed-point through a year in Guangzhou. The results shew that the water transpiration yearly (1395 trees per hectare) is 4817.60 ton/hectare, 9944.06 ton/hectare, and 13631.72 ton/hectare, respectively by Eucalyptus torelliana, Cunninghamia lanceolata and Acaia auriculaeformis.Statistical analysis proved that the variance of transpiration rate is mainly limited by the environmental factors of light intensity and temperature. The practical equation established from multiple regression analysis is a simple method to measure the transpiration rate for those tree species.