A number of podophyllotoxin derivatives were analyzed by AM1 method. Some information from the calculation results and the inhibition of L1210 indicate that there are three structurally distince domains: The C4 position is an effective modified point. The B ring and E ring are important active centers. The results also show that the hole of positive charge in B ring easily combines with an acceptor within the molecule. The E ring along with its C4'xyl group is an important center of negative electricity.

Key words: ANTINEOPLASTIC ACTIVITY, QUANTITATIVE STRUCTURE ACTIVITY RELATIONSHIP, INHIBITION (BIOLOGICAL SCIENCE), QUANTUM CHEMISTRY