Abstract：Using seasonal decomposition and HP filter method，this paper decomposed the wholesale prices of 28 vegetables into trend fluctuation，cyclical fluctuation，seasonal fluctuation and random fluctuation for more details of the characters and laws for different vegetables，and summarized the differences between different vegetables price fluctuation and changes. The results indicated that in recent years the impact of seasonal
fluctuation to vegetables price fluctuation became gradually weaken，while the impact of random fluctuation to fruit and leafy vegetables was strengthened constantly. There were big differences in the influences brought by different fluctuation types on vegetable prices. Fruit vegetable price was more significantly affected by seasonal fluctuation.While leafy vegetable price was more easily affected by random fluctuation. Cyclical fluctuation had remarkable impacted to ginger and garlic price fluctuation.