Abstract: This paper discussed the effects of potassium fertilizers varieties and potassium application stage on yield and quality of potato by field experiment. The results showed that potassium fertilizer application had yield-increasing effect on potato production. The yield-increasing effect had manifested as irrigable land 10.9% and rain-fed 12.7%. Muriate of potash, potassium sulphate and nitrate of potash did not have obvious different effect on potato output. The sequence of fertilizer application stage effect on output was basal application 〉half dressing and basal application 〉dressing with no obvious differences. The potassium fertilizer application could increase the proportion of potato which the sequence was basal application〉half dressing and basal application〉dressing and the fertilizer varieties had no difference for potato proportion. The potassium fertilizer application had decreased the color value of fries and content of reducing sugar, the sequence of reducing sugar was potassium sulphate 〉muriate of potash〉 nitrate of potash. In addition, the potassium fertilizer application also had increased the content of starch, but the potassium fertilizers varieties and potassium application stage had no obvious difference effect on content of starch and color value of fries. The fertilizer utilization was 37.1% for rain-fed potato and 37.3% for irrigable land potato. Muriate of potash application effect was higher than others in potassium fertilizers varieties aspect. In potassium application stage, the fertilizer utilization effect was basal application〉half dressing and basal application〉dressing. Finally, every tons of potato production need assimilate 6.16 kg K2O in irrigable land and 4.99 kg K2O in rain-fed land.