Abstract: An experiment about a fertilizer synergist——Kangfuwei that was applied on potato was carried in 2008.After sowing seeds, we compared the effect of applying the regular fertilizer with applying only Kangfuwei on an area where was applied fertilizer in last fall traditionally. The results indicated that the average yield applied Kangfuwei was 20616kg/hm2 Comparing to regular fertilizer ,the difference was not remarkable. This method raised the fertilizer use factor and saved the fertilizer, it may promote the application on the potato.