Abstract: The results from different straw-returning applying decomposing agent treatments showed that the treatment adding decomposing agent and combined application of urea in straw composting process could accelerate straw moulding degree and promote the growth of broad bean significantly after returning decomposed straw, the broad bean yield reached 527.0 kg/667 m²(7905.0 kg/hm²) and significantly higher than other treatments. Meantime, the treatment could raise the soil organic matter and various available nutrient contents, decrease soil bulk density, increase the cation exchange capacity and improve the soil physical and chemical character.