The lettuce yield and root distribution were studied in four cultivation substrates under drip and micro-sprinkler irrigation. And the vertical distribution model, lettuce yield and root length density model, and the differences and the similarities of root density relative distribution on profile were analyzed. The obtained results showed that the substrate moisture mainly distributed in lower level and evenly in 0~15 cm respectively under drip irrigation and micro-sprinkler irrigation. The lettuce root length density cultivated in compound substrates were higher 27% at least than that in pure vinegar cultivation. More than 71% of the root system was mainly distributed in shallow substrates(0~6 cm) under micro-sprinkler irrigation. The lettuce yield cultivated in compound substrates were higher 10% at least than that in pure vinegar cultivation, and was higher 22% at least than micro-sprinkler irrigation in spring, while it was lower 11% at least in summer.