Abstract: Influence factors on ultrasonic-assisted extraction process of tea polyphenols were studied.During the process of ultrasonic-assisted extraction, the change rule could be found in different tea, solvent, solid-liquid ratio, temperature, time, power, frequency and extract series.Results showed that extraction rate would be higher and leveled off in the end if the size of tea, fermentation time and pH value became smaller, frequency and extract series became greater.And the extraction rate first increased and then decreased with the solid-liquid ratio, temperature, time and power augmenting.