Abstract: The stem segments, leaves and petioles of three herbaceous peony was used as explants for somatic embryogenesis. Paraffin method was used for morphological and histological observation of somatic embryogeneris. The main conclusions were as follows: callus induction rate from stems of ‘Going Bananas’ was 100%. Proliferation rate of the callus was over 4.0. The best induction and proliferation medium of inducting callus was WPM+IAA 1.0 mg·L^-1+6-BA 1.0 mg·L^-1+NAA 0.5 mg·L^-1+TDZ 0.5 mg·L^-1+CH 0.625 g·L^-1. Embryogenic callus generated after transferred the callus to 1/2 MS(Ca²⁺ doubled)+2,4-D 2.0 mg·L^-1+ABA 0.5 mg·L^-1 or ZT 1.0 mg·L^-1 medium of a constantly dark cultivation of 90 d. Globular embryos and heart embryos were generated after transferred the embryogenic callus to 1/2MS(Ca²⁺ doubled)+6-BA1.0 mg·L^-1+NAA 0.2 mg·L^-1 medium for a constantly illumination cultivation of 60 d. There are exogenous and endogenous origins of somatic system. Exogenous includes origins from individual surface cells and origins from multiple subcritical cells. The difference of three ways lies mainly in starting position and starting cells number, they will all generated proembryo later. The splitting of embryogenic cells was symmetrical and the presence of asymmetric splitting cells was not found.

Key words: herbaceous peony, somatic embryo, origin, histocytology