Abstract: In order to search for new antitumor drugs, sixteen N′, N″-dispirotripiperazine derivatives were synthesized from N′, N″-dispirotripiperazinium dichloride dihydrochloride by substitution, acylation and Mannich reaction. Six compounds were selected for preliminary pharmacological test. The result showed that five compounds possess inhibitory action against carcinoma S₃₇ in rats. The inhibitory activity of compounds Ⅵ and Ⅹ was 55.0% and. 41.9% respectively.