A three-year field experiment was carried out to explore effects of timing of plastic film mulching and freezing saline water irrigation (FSWI) on salt and water dynamics in coastal saline soil and cotton growth. The experiment was designed to have five treatments, that is, mulching after ice melt percolation (MI), mulching after sowing with FSWI (SI), no mulching with FSWI (NI), mulching in autumn without FSWI (AN) and no mulching without FSWI (CK). Results show that in the plot with FSWI, ice melt decreased salt content and soil adsorption ratio (SAR) in the surface frozen soil layer gradually from 12.15 g L^-1 and 18.7 to 0.03 g L^-1 and 1.07, respectively. During the three years of FSWI, the soil salt content in the surface soil layer decreased year by year according to the measurement at the same time period. In 2006, 2007 and 2008, the soil salt content in the top soil (0～20 cm) before FSWI was 19.8, 15.4 and 12.4 g kg^-1, respectively. In the plots after freezing saline water irrigation, all the water and salt from irrigation and large number of water and salt from soil was leached to the soil layer below 1m. Soil salts came back quickly after the melt percolated down the profile. So mulching 9 days after melt percolation would obtained a better effect of preserving soil water and inhibiting return of soil salt. The effect of Treatment MI was the best, and so was its effect on seed germination rate and seed cotton yield, which was 63.78% and 3 200 kg hm^-2, respectively. The treatment was followed by Treatments AN, SI, NI and CK, in effect. After the three years of FSWI, Treatment AN also obtained a high germination rate of 59.63% and a high yield of 2 600 kg hm^-2 in the fourth year though when there was no freezing saline water irrigation. While in the plots of no mulching or later mulching, no ideal yield was obtained even though they received FSWI in all the three consecutive years.