Objective: To study the separation technology of total flavonoids from leaves of Lonicera japonica and investigate their antibacterial activity in vitro against nine common pathogenic bacteria. Method: The leaves of L. japonica from Henan Fengqiu were used

and the total flavonoids were obtained by macroporous resin column separation as the main investigation indexes. Then their antibacterial activity in vitro were evaluated by minimum inhibitory concentration (MIC)

minimum bactericidal concentration (MBC) and inhibition zone. Result: A simple and convenient separation technology was established

proving the broad and better antibacterial activity against nine common pathogenic bacteria (MIC values were 1.95-62.5 g·L-1

and MBC values were almost 125 g·L-1). Meanwhile

when the total flavonoids fraction coexisted with plenty of chlorogenic acid (4.2%)

its yields (10.5%) and activity were higher. Conclusion: The total flavonoids from the leaves of L. japonica could be developed as the antibacterial agent or feed supplement for livestock and poultry because of their broad and better antibacterial activity

and this study will lay the foundation for the rational development and utilization of the leaves of L. japonica.