Ultrasonic wave-assisted extraction of Antrodia camphorata's mycelim was studied. Four test factors of solid-to-liquid ratio, ultrasonic power, extraction temperature and extraction time were studied in extraction of polysaccharide and triterpenoids from Antrodia camphorata. Ultraviolet-visible spectrophotometer was used as determining method. The results showed that the extraction quantity of polysaccharide was 26.319 mg/g with 120 W ultrasonic power lasting for 35 min, under 55 ℃ with the solid-to-liquid ratio of 1︰30 (m︰V). The extraction quantity of triterpenoids was 38.624 mg/g under the optimal extraction condition which involves solid-to-liquid ratio of 1︰30 (m︰V), ultrasonic power of 210 W, extraction temperature of 50 ℃, extraction time of 25 min.