Some special years were identified by using the singular value decomposition(SVD) analysis between 500 hPa height fields and Shandong precipitation in the same periods: July,August and summer,respectively.The 500 hPa height fields in special years were synthesized,and the results indicate: The unconventionality of the position and strength of the western subtropical high has an important influence on Shandong precipitation.While the western subtropical high is weaker and its position is farther northern,there is more rainfall in Shandong;and while the western subtropical high is stronger and its position is farther southern and western,there is less rainfall in Shandong.In addition,the unconventionality of the 500 hPa height field over the South China Sea and Philippines has close relation with the western subtropical high.