Abstract: In the report， the temperature， precipitation and sunshine observation data of Hainan island 19 national meteorological observation stations during 1966-2022 were used to analyze and compare the different characteristics of temperature， precipitation and sunshine duration between the new climate state （1991-2020） and the old climate state （1981-2010） in Hainan island， and the influences of climate state replacement on climate operations were also analyzed. The results showed that （1） The climate in new climate state is warmer than that in old climate state all over Hainan island， the warming amplitude of annual mean temperature is higher in the northern half than that in the southern half， the annual mean minimum and mean maximum temperature are both higher too， and the average minimum temperature increases mostly. The temperature is consistently higher in each month. High temperature days of different thresholds both increases； （2） The climate in new climate state is wetter than that in old climate state in most areas， the difference between new climate state and old climate state is characterized by monthly inhomogeneity and spatial inconsistency， which are wetter in winter and summer， the increase of humidification is most significant in summer， and which are drier in spring and autumn. Under the new climate state， the occurrence probabilities of rainstorm， heavy rainstorm and above grade extreme precipitation increase in Hainan island； （3） The annual average sunshine duration of the new climate state is generally less than that of the old climate state， the monthly distribution is inhomogeneous； （4） The climate state replacement has certain influence on climatic impact assessment， climate prediction operations， and climate service in Hainan island， especially for the regions and months with large difference between the new climate state and old climate state.