This study was carried out to evaluate cytotoxicity of the methanol extract from Sophora flavescens Ait. against L1210 (lymphocytic leukemia) and $P388D_1$ (lymphoid neoplasma) Cells in vitro. We have determined cytotoxicity by the MTT (3- (4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H- tetrazolium bromide) assay. The order of cytotoxicity of Sophora flavescens Ait. extracts against L1210 and $P388D_1$ cells in vitro is as follows: Fr. 4 > Fr. 3 > Fr. 5 > Fr. 2 > Fr. 1. These results suggest that the fraction 4 of the methanol extracts from Sophora flavescens Ait. may be a valuable choice for the development of antitumor agents. In order to develop an antimicrobial agent, dried Sophora flavescens Ait. was extracted with hot methanol, and then antimicrobial activity (MIC test) was investigated. In this study, the fraction 3 of the methanol extracts from the roots of S. flavescens showed strong growth inhibition activity against gram-positive and gram-negative bacteria (MIC, $3.125;{mu}g/ml$) such as S. mutans, S. epidermidis and P. putida. These results indicate that fractions 3 and 4 inhibit tumor cells and bacteria.