Abstract: Ten compounds of dipiperazine diquaternary ammoniums were synthesized from1-benzoylpiperazine by N-alkylation , quaternization and debenzoylation. The results of toxicitv andantitumor activity tests showed that, the greater the n and R in V, the higher the toxicity;Vc(n=6,R=CH3)and Ve(n=6,R=C2H5),which had middle fat solubility,possessed different activitiesagainst carcinoma S37 and quaternary ammonium plays a certain part in adjustment of oil-waterparrtition coefficient.