Twelve quinolizidine alkaloids were isolated from Sophora tonkinensis by means of silica gel, preparative MPLC, and preparative HPLC. On analysis of NMR spectroscopic data, their structures were established as 3-(4-hydroxyphenyl)-4-(3-methoxy-4- hydroxyphenyl)-3,4-dehydroquinolizidin (1), lanatine A(2) , cermizines C(3 ) , senepodines G( 4) , senepodines H( 5) , jussiaei- ines A( 6 ), jussiaeiines B( 7 ) , ( + ) -: A-hydroxyoxysophocarpine ( 8 ), ( - ) -12/3-hydroxyoxysophocarpine( 9 ) , ( - ) -clathrotropine (10) ,( - )-cytisine( 11) , and ( - )-/V-methylcytisine(12) , respectively. Compounds 1-7 were first isolated from Sophora L plant. In the in vitro assays,the isolated compo nds 1,3, 6-10 exhibited potent activity against CVB3 with IC50of 6. 40, 3. 25, 4. 66, 3. 21 , 0. 12, 0.23 and 1.60, and with selective index values(SI = TC50/IC50)of 12.0, 5.6, 13.0, 15. 1, 50. 1, 26.2, and 23.6, respectively. Compounds 1,3, and 7 exhibited activity against staphylococcus aureus( ATCC 29213)with MIC values of 8. 0, 3. 5 , 6.0 g • L-1, respectively. Compounds 1, 3, 7, and 12 exhibited activity against staphylococcus aureus (ATCC 33591) with MIC values of 18. 0, 7. 5, 8. 0, 12. 0 g • L -1, respectively. Compounds 2,6,7 exhibited activity against Escherichia coli{ ATCC 25922) with MIC values of 1.0, 3. 2, 0. 8 g • L-1,0.