Abstract: To clarify effect of high-temperature germination technology on rice seed germination, agronomic traits, and yield, determine optimal germination temperature, and accelerate application of high-temperature germination technology in agricultural production, different temperature settings of rice seed germination machine were tested．Five temperature gradient treatments were set up, W₁（20 °C）、W₂（30 °C）、W₃（40 °C）、W₄（50 °C）and W₅（60 °C）, then seeding in two types of planting environment of field and laboratory．Results showed that germination percentage, field agronomic traits and yield of rice seeds showed an increasing and then decreasing trend with increase of germination temperature, and the maximum value was achieved in W₄, germination percentage, plant height, stem thickness, dry matter accumulation, spikelet numbers per spike, grain numbers per spike, thousand grain weight and yield of 96.83%, 92.89 cm, 6.64 mm, 2.73 g/plant, 3.85 million spikes/hm², 102.31 spikes/grain, 31.24 g and 8995.05 kg/hm², respectively．Therefore, considering germination percentage, agronomic traits, and yield performance of rice under different germination temperature treatments, optimal germination temperature was 50 °C for rice seed germination machine in rice planting and production in Tianjin City．