Rubber seeds are recalcitrant seeds and cannot withstand intensive desiccation. The time from seed falling off rubber tree to seed sowing is crucial for germination and seedling growth. The present study compared the sowing time effect of GT1 and Reyan73397 seeds after harvest on germination and seedling growth. The results showed that GT1 seeds after harvest should be sown during 3 days and Reyan 73397 seeds should be sown during one day, seed germination was negatively correlated with seed width and seed weight, seedling plant height and leaf SPAD value was negatively correlated with seed length. Taken together, seed sowing time affects seed germination and the growth of rubber seedlings, and understanding seed sowing time effects helps to collect and transport seeds timely so as to sow and obtain high-quality rootstock seedlings.