Experiments on plastic mulching were carried out in northern area of Yinshan Mountain in 2008 and 2009 to alleviate the pollution caused by mulching film residue and improve the water use efficiency in arid area. Research of different mulching treatments on soil temperature, soil moisture and the growth and development of potato were studied. The results showed that temperature of three degradable plastic films same as the ordinary plastic film. Water use efficiency of degradable film C was 73.25 and 63.05 in 2008 and 2009 respectively, were higher than the other two kinds of degradable film. From the point view of potato growth and development, emergence of three kinds of degradation film was significantly higher than ordinary film, but plant height and leaf number was significantly lower than ordinary film. There was no significant difference from different kind of film. The insulation effect of degradation film was good, but water retention was relatively poor; The main growth limiting factor of local crop was water from years of practice, so promotion of the degradable film in the arid zone has yet to be considered.