Three years experiments of soil and water conservation with biological treatments such as planting creeping orchid on terrace walls and interplanting soybean, peanut, etc. on terrace levels in mountainous young orange orchard indicated that, the effects of soil and water conservation increased by 395.4 - 412.0% over control; alkalized nitrogen in soil increased by 316.6-466.0% over control, available P increased by 233.3 - 333.3% and available K increased by 85.7 - 100%. The amount of sprouted shoots of orange increased by 48.2 - 71.42% over control and the fruit yield per tree increased by 58.7 - 75.2%.