Taking tomato（Lycopersicon esculentum Mill.）cultivar‘Zhongza105’as experimental
material，this paper studied the effects of different sun-shade nets and tranditional black sun-shade nets on
inside light and temperature environment，tomato seedling growth and physiological properties．The result
showed that with the decreasing of shading rate，photon flux density（PFD），air temperature，5 cm and 10
cm soil temperatures all showed an increasing tendency．Compared with the 50% shading rate of black net，the
transmittance of 50% white net was remarkably different．The black sunshade net has higher UV transmittance
rate and there were not much differences between the transmittance rates of infrared light and visible light．While
the transmittance rates of UV light and part of infrard light of white sun-shade net was significantly lower than
the visible light．Therefore，the white sunshade net used as outside shading net of greenhouse could have better
cooling effect．Along with the decreasing shading rate，both black and white net treatments were all helpful for
increasing plant height，stem diameter，leaf area，total biomass，sound seedling index，root system activity and
foliar blade thickness of tomato seedling．Summing up the above，in summer according to the actural condition of
tomato seedling development，sunshade nets with shading rate between 20%-40% might be a good choice，among
them the white sun-shade net with 20% shading rate had the better effect．