For a comprehensive understanding of climate in a greenhouse with fan and pad system, an experiment measuring climate parameters was conducted on with two ventilation rates and with pad on and off. The transpiration rate of the plant inside greenhouse was supposed to be one of the most important factors on climate considerably influences latent heat exchange, and it was calculated and measured mainly in this work. The experimental data show that the transpiration rate has some correlation with ventilation and pad working condition. In the case of no pad working, the higher ventilation which promotes transpiration will induce a lower temperature inside greenhouse to outside and a lower leaf temperature than its ambient temperature. But with the pad working the leaf phenomena is just opposite. The vertical and horizontal distribution of temperature and specific humidity were also measured and analyzed.