Besed on the observation data,thermal effect of environmental conditions in Shijiazhuang is analyzed in detail.The results indicate that the greenbelt of city can adjust the local temperature.The ground temperatures of different underlying surface have obvious diversity.The building or underlying surface,such as asphaltum and cement surfaces have contributed to the increasing temperature of the city.The city enlarging,buildings and hard road surface increasing,and greenbelt reducing are the primary cause which makes the city form thermal island effect.