Tartary buckwheat (Fagopyrum tataricum) seeds were treated using ultrasonic at different power and time and temperature. The exposed grains were germinated, then harvested after incubation on the 2rd, 4th, and 6th days. The effects of ultrasonic on the germination rate of the tartary buckwheat seeds and some nutrient compounds in the sprouts were detected, and the DPPH radical-scavenging activities of the seedlings were investigated. The results showed that with treatment of 280 W ultrasonic, at 20 ℃ for 35 min, the highest rates of initial (88.0%) and final (100.0%) germination were obtained after incubation. With the treatment of 240 W ultrasonic, at 15 ℃ for 35 min, the seedlings produced the highest contents of the reduced sugar (11.24 g/100 g) after 4 day of incubation, and this was 303.99% and 40.03% more than those in the seeds and the control, respectively. A treatment of seedlings of 280 W, at 30 ℃ for 30 min got the highest the total flavones contents, i.e., 9.46 g/100 g after 6 day of incubation, which was significantly increased by 228.07% and 69.71% compared to those in the seeds and the control, respectively. Moreover, the DPPH radical-scavenging activities of the seedlings was found to be 86.47%.