Abstract: The effects of different types of plant growth regulators, concentration and treatment time on the rooting of softwood cuttings of Alnus rubra were studied by taking the first year tender shoots as experimental material, and the rooting mechanism was explored by anatomical observation. The results showed that the best rooting effect of A. rubra softwood cuttings was obtained by soaking the cuttings with 250mg /L GGR-6 solution for 2h. The rooting mechanism was mixed though bark rooting was the main type, and the roots mainly took place within 15cm length from the lower end of the cuttings. The adventitious root primordium of the cuttings was mainly differentiated from the vascular cambium parenchyma cell and callus cells between the pith ray and cambium.