Abstract: Four methods of irrigation, trickle irrigation, portable sprinkling irrigation, porous pipe sprinkling irrigation and furrow irrigation were tes ted. It was found that all with trickle irrigation, portable sprinkling irrigation and porous pipe sprinkling irrigation have remarkabler effect on water saving than furrow irrigation. They were saving water over 50 per cent. These methods of irrigation except the furrow irrigation all made lower relative humidity in plastic house, which may shorten the time of dewing at night, and may reduce or prevent from the diseases of cucumber. The advantages of porous pipe sprinkling irrigation include the easy connection of the pipe equipment, the rarely stop of the hole of spray pipe and the lower cost. It is a relative method of irrigation for growing cucumber in plastic house at present. The bigest yield of spring cucumber was produced at the pressure of soilmoisture to 330 or 450mm Hg. In this case the moisture content of soil is to 22.8 per cent , and equal 80.3 per cent of field capacity. The parameters mentioned before may be used as a guide in determining when irrigation is necessary for growing cucumber in plastic in the region of Changchun, Jilin Province.