Abstract: Abstract: Buried straw layer plus plastic mulching has been recommended as a good practice for ameliorating soil salinity and increasing crop yield, but its influence on the soil water and salt distribution and the change of microflora in the case of different quota of spring irrigation has not yet been determined. In this paper, a micro-plot field experiment was conducted to study the effects of straw interlayer with plastic mulch under different amount of spring irrigation on the soil water and salt distribution, soil microflora and sunflower yield on a moderate saline soil in the Hetao Irrigation District, Inner Mongolia of China. Five treatments were designed: irrigation amount of 2 250 m3/hm2 with no straw interlayer (CK), irrigation amount reached 100% (W100), 90% (W90), 80% (W80) and 70% (W70) of CK with straw interlayer. The results showed that the water content in the 20-40 cm soil layer under the treatments with straw interlayer increased with the increase of spring irrigation amount, and W100 treatment significantly enhanced water storage capacity in the 0-40 cm soil layer by 6.5%, 3.6%, 5.8% and 8.9% compared with CK, W90, W80 and W70 after spring irrigation (P<0.05), respectively. Both W100 and W90 treatments had good desalting effect after irrigation and the salt could be leached down to 50-60 cm deep, also the salt content in the 0-40 cm soil layer was decreased by 18.9% and 13.9% compared with CK (P<0.05), respectively. Accordingly the desalination rate in the 0-40 cm soil layer under W100 and W90 were 34.9 % and 30.1 % higher than CK (P<0.05), respectively, but there was no significant (P>0.05) difference in soil salinity and desalting rate between W100 and W90 treatment, and also no significant (P>0.05) difference was found between W80 and CK. At harvest, the water content in the 0-40 cm layer under CK was significantly higher than that of other four treatments (P<0.05), while the salt content in the 0-40 cm layers under W100 and W90 was lower 27.6% and 16.3% compared with CK (P<0.05), respectively. However, there was no significant difference (P>0.05) in salt content between W100 and W90 treatments; also the difference between W80 treatment and CK was not significant (P>0.05), while the soil salt content of W70 was significantly higher than other treatments. Compared to CK, W80 and W70, both W100 and W90 treatments significantly increased the quantity of bacteria, antinomies and fungus (P<0.05), also the species of dominant microflora was increased. We also found that W90 treatment was more favorable to the growth of soil fungi than W100. After harvest, the yield of sunflower treated with W100 was significantly higher than that of the other four treatments (P<0.05), and increased by 5.3%, 6.8%, 11.4% and 13.6% compared with CK, W90, W80 and W70, respectively. There was no significant difference between W90 treatment and CK (P>0.05), but its water productivity was significantly higher than that of CK (P<0.05). In summary, only from the angle of high yield, the current level of spring irrigation with straw interlayer (W100) was recommended since the most obvious increasing effect of sunflower yield. Considering the soil desalination, stable crop yield and increasing water productivity, the straw interlayer combined with the 10% reduction of local spring irrigation amount (W90) was also a locally recommended measure.