The paper aims to explore the effects of extraction treatment of ultrasonic with different frequencies assisted with deionized aqueous solution on extractive yield, components and dimensional stability of E.grandis×E.urophylla. The E.grandis×E.urophylla samples were extracted in deionized water, 1% hydrochloric acid solution and 1% sodium hydroxide solution at 60 ℃ for 2 h at ultrasonic frequency of 0, 25 and 59 kHz, respectively. The extractive yield, the sample swelling ratio and the anti-swelling efficacy were calculated, and the extractive components were detected by GC/MS. The sample with the frequency of 59 kHz ultrasound assisted with 1% sodium hydroxide solution had the highest extractive yield, up to 7.67%. The components of the extractives obtained by three kinds of solutions had a large difference, but the types and relative contents of alkanes and esters changed apparently during ultrasonic-assisted extraction; the extraction treatment improved the dimensional stability of the samples. The sample with the frequency of 59 kHz ultrasound assisted with 1% hydrochloric acid solution had the highest anti-swelling efficacy, up to 65.39%. The extraction treatment by ultrasonic synergistic hot aqueous solution can improve the dimensional stability of the E.grandis×E.urophylla and facilitate the extraction of the extractive.