This paper studied effects of start fertilizer on drip irrigated maize growth，yield and soil characteristic in calcareous soil.The maize varieties is ‘Xin yu 109’(Zea Mays L. Xinyu 109)，four starter fertilizer levels[0 kg·hm-2(CF)，45 kg·hm-2(SF3.0)，90 kg·hm-2(SF₆.0)，135 kg·hm-2(SF9.0)]were conducted in a field experiment but keep total P application identical in the whole growth stage of maize，aimed to analyze the effects of application amount of start fertilizer on soil fertility，yield and economic benefits of maize，the reasonable application amount of start fertilizer was determined. The results showed that:(1)After three days of starter fertilizer application，the available P increased by 9.20 mg·kg-1 on average，and the available Zn increased by 0.28 mg·kg-1 on average in 0～10 cm soil layer and 5 cm away from the dripper.(2)Application of start fertilizer promoted the growth of maize root system，significantly improved the number of maize node roots，average diameter of root，and total surface area，total volume of root.(3)Compared with CF，the starter fertilizer increased the yield of maize significantly，the highest maize yield of the starter fertilizer treatment was 22731.9 kg·hm-2，and the yield increase rate was 15.99%.The net income increased from 15474.9 yuan·hm-2 to 20028.3 yuan·hm-2. The income of SF3.0，SF₆.0 and SF9.0 increased by 4.1%，29.4% and 9.4% respectively，and the out/input ratio increased from 2.19 to 2.54. SF₆.0 showed best performance in yield and profit in all the four treatments. The reasonable application amount of starter P2O5 is 35 kg·hm-2.