Different water treatments（80%，70% and 60% of field water holding）of summer maize crop coefficient under conventional furrow irrigation and controlling alternative furrow irrigation by using single crop coefficient method FAO recommended were studied. The results showed that irrigation pattern correction coefficient was available to be indicated by the relative amount transpiration and having a good relationship of 6 times a function with the days after sowing. With different furrow irrigation ways，single crop coefficient showed the same pulse fluctuations trend，but in alternative furrow irrigation crop coefficient was smaller than conventional furrow irrigation. The crop water requirement deviations between that calculated by using single crop coefficient method and the measured value were less than 10%，which was in good agreement.