Global commodities price grew fastly after 2002 which is pushed by excessive liquidity worldwide.In this report，we analyzed the impact of global excessive liquidity on commodity market based on wheat future and copper future.According to analysis here，the impact of liquidity is apparent.However，commodity price is driven by other factors in the same time.Generally speaking，the speculating in wheat future market is larger than copper future market，while the later is driven mainly by demand from industrial expansion.