Abstract: This study aims to investigate the effects of seed soaking with humic acid fertilizers and irrigation on seeds germination and seedlings growth of oat. The oat seeds were taken as study materials, and the standard germination test method and habitat soil culture method were used in laboratory to measure a series of indicators related to seed germination and seedling growth after the seeds were pre-soaked with humic acid fertilizers and the seedlings were irrigated. The results showed that there was no significant effect of humic acid fertilizers on the vitality of seed. However, potassium humate improved the speed of seedling emerge significantly (P＜0.05), it also improved the seed germination. Fulvic acid, sodium-rich humic acid fertilizer and sodium humate reduced the speed of seedling emerge and the vigor index of seed. The data on the seedling growth suggested that potassium humate had positive promotion effect on the amount of seedling growth, the length of stems and roots and the rate of rooting; fulvic acid, sodium-rich humic acid fertilizers and sodium humate all accelerated the growth of stem and root too, but they all inhibited the rate of seminal rooting, which was adverse to the survival and stress-resistance of seedling. The results also showed that all kinds of the humic acid fertilizers tested in this study improved fresh weight of seedling, the amount of root, root-stem ratio, root-cap ratio and tillering ability of the seedling after irrigated at seedling stage. Potassium humate was the best humic acid fertilizer for seed-soaking before sowing and all kinds of humic acid fertilizers tested could be used as irrigation fertilizer for oat seedling.