Abstract: Field experiments were conducted to study the effects of the different rates of potassium sulfate(SOP) and potassium chloride (MOP) on the yield, quality and nutrients uptake under field and plastic shed conditions. The results showed that the K fertilizer could increase the cucumber yield and SOP increment was higher than MOP. The application of SOP in cucumber at the plastic shed could obtain higher yield and nutrient utilization efficiency. Potash increased the Vc, sugar contents and MOP was better than SOP. The amino acid (AA) contents of cucumber with of low and middle rates of SOP were higher than that of MOP, but the nutrition value of essential AA was lower than MOP. K application could increase K content of cucumber, while other nutrients was decreased. The ratio of nutrients partition in cucumber fruit with SOP were higher than that with MOP. MOP was conducive to the nutrient accumulation in vegetative tissues of cucumber. The differences in the effects of potash sources on the yield and qualities provided the possibility for mixed use of SOP and MOP in cucumber cultivation.