By taking the data from five stations without heat-island effect as reference,the heat-island characteristics in the coastal cities of Guangdong Province were investigated based on the air temperatures data from meteorological and oceanographic stations nearby the coastal regions during 44 years between 1960 and 2003,and the impact characteristics of heat island on eighteen coastal meteorological stations were assessed respectively.The results indicate that,to a great degree,the fourteen meteorological stations are affected by heat-island,except four of the eighteen stations.Intensity of heat-island is from 0.4 to 0.8 ℃ over the past ten years with significant seasonal variations.Due to the heat island impact,the annual mean air-temperature is increased by 0.1℃/10a to 0.3℃/10a in the recent 30 to 50 years,in comparison with reference stations.