Abstract: Based on Yunnan 124 observation stations data,Arctic Oscillation(AO) Index and Niño34 Index,the influence of AO and sea surface temperature (SST) anomaly on the distribution of the winter(spring) precipitation in Yunnan have been analyzed.The results show that firstly,during winter,when AO is positive or negative phase,Yunnan precipitation (YNP) will rise or fall all year around.During spring,when AO is positive phase,YNP will increase at most places.To the negative phase of AO,YNP will drop at most places.Secondly,when Niño34 SST is at positive phase,Yunnan winter precipitation will increase at most places except eastern areas.While it is at Niño34 SST negative phase,winter precipitation will increase in the whole Yunnan.During spring,when Niño34 SST is positive phase,Yunnan precipitation usually falls in almost the whole province.And Yunnan precipitation commonly increases all around under the negative phase of Niño34 SST.Thirdly,the combined influence of AO and Niño34 SST on Yunnan winter/spring precipitation shows that winter and spring precipitation is affected by AO (Niño34 SST) more obviously.Fourthly,the influence of AO on Yunnan winter precipitation can be promoted by ENSO warm episode,and there is a significantly positive correlation between AO and Yunnan winter precipitation.What’s more,AO almost has no effect on Yunnan winter precipitation when ENSO clod event happens.In addition,when ENSO event occurs,it seems that AO has little impact on Yunnan spring precipitation.This also indicates that the influence of AO on Yunnan winter precipitation is regulated by ENSO more significantly than it is to the spring precipitation.Finally,when predicating winter precipitation,more attention should be paid to AO than SST during winter,and as for spring,our attention may get reversed.