Objective To study the inhibitory effect of ibandronate(IBN)on the growth of lung cancercell line PLA-801D in vitro,and the mechanism of such effect was studied.Methods The effects of different doses or treatmenttime of IBN on the growth of PLA-801D cell line were detected by MTT method.The mechanism of the effect was analyzed by the examination of cell cycle using flow cytometry.Results With the concentration of 10 to 100 ?g/ml,IBN obviously inhibited the growth of PLA-801D cell(P