From the 70% EtOH extract from the roots of Paeonia lactiflora (Paeoniaceae), nine triterpenoids were isolated and identified as ${eta}-amyrin$ (1), 24-methylenecycloartanol (2), betulinic acid (3), oleanolic acid (4), hederagenin (5), 30-norhederagenin (6), 30-norarjunolic acid (7), arjunolic acid (8), and $3{eta},4{eta},23-trihydroxy-24,30-dinorolean-12,20(29)-dien-28-oic$ acid (9) by spectroscopic methods. Among these compounds, 1, 2, 7, 8 and 9 were isolated for the first time from this plant.