Abstract: On consulting academic documents, a series of experiments were carried to study the effect of wood vinegar on seed germination and seedling viability of summer squash (Cucurbita pepo L.). Different concentrations of wood vinegar were adopted to soak summer squash seeds with dilution of 100 times, 300 times and 500 times for 6 hours, and seeds soaked with the same volume of distilled water for the same duration were taken as the control. The test results showed that wood vinegar had effects on soaked summer squash seeds in terms of germinability, germination rate, the length of sprout, the length of seedling, fresh and dry weight of seedlings (100pc), and plant vigor index. According to the test results, different dilution ratios had different effects, M₁₀₀ had the best positive effect, the vigor index was 9.01% higher than that of the control, the fresh weight, dry weight, root length increased by 13.47%, 9.81%, 15.79% respectively compared with that of the control, while the effect on sprout length and germination was unobvious. The study concludes that the wood vinegar can stimulate the root growth of seedling, raise fresh and dry weight and the vigor index, therefore, it can be the material for soaking summer squash seeds before sowing.