Abstract: The effects of light, temperature and relative humidity on the transpiration rate of Murraya paniculata are studied in a field in Caishan township of Yingde county, a limestone area in Guangdong province. The transpiration rate of the plant has no linear relation with any tested factors. There is no linear relation between transpiration intensity and the aperture of stomata, either. The intensity and diurnal amount of transpiration by M. paniculata are relatively small, representing a charactor of plants in limestone regions.