alysed by testing cellular micronuclei of root-tip cells of Vicia faba．The results showed that the cellular micronuclei frequency decreased significantly．Green tea and Oolong tea were more effective than white tea and black tea, but there was less difference between green tea and Oolong tea, so as white tea and black tea．At the same time, the tea-liquid/water ratio of 1/50 was also more effective than that of 1/100．The effects were positively correlated with catechins．It could be deduced that drinking tea could control the harm from cigarette smoke.

　　Key words　tea; water-soluble substance contained in cigarette smoke; micronuclei frequency; catechins

　　微核(micronucleus)是真核类细胞中的一种异常结构,它通常是由各种理化因子对分裂细胞作用而产生的.微核高峰出现在畸变高峰之后，染色体的畸变是导致微核形成的重要因素.由于微核形成和染色体畸变的一致性，微