To study the effects of lower limit of saline water mulched drip irrigation on water salt transport and corn yield, a field experiment about mulched drip irrigation of corn with saline water was conducted in Changsheng experimental station. Tensiometer was used to guide irrigation, in each treatment the matric potential of soil 20?cm depth under the emitter was controlled higher than -10 kPa, -20 kPa, -30 kPa, -40?kPa, respectively. All treatments were repeated three times with the experimental plots following a complete randomized block design. Results showed that the shape of wetted body of mulched drip irrigation on sectional elevation of emitter which was perpendicular to the drip irrigation belt was approximated to semi-ellipsoidal. The water content of wetness soil layer would increase with increasing irrigation lower limit. The zone near maize root of all treatments appeared low salinity zone, surface layer out of the plastic film appeared high salinity area; -20?kPa and -30?kPa irrigation lower limit were moderate, they not only could leach surface soil salinity in the mulch more fully, but also did not lead to the salt in brackish water accumulation. All treatments 100?cm under the surface in and out of the mulch during growth of corn occurred salt?deposit. The depth of wetting layer of -10?kPa and -20?kPa irrigation limit were both about 60?cm. After maize harvest, all treatments occurred salt accumulation under the surface 100?cm, to ensure land salinity not accumulated year by year, massive irrigation to leaching large number of soil salinity in autumn or next spring was required. When irrigation frequency was too low, the maize yield decreased with decreasing irrigation frequency. Under the experimental conditions, the maize yield decreased with decreasing irrigation limits.