Abstract: Vicia-micronucleus test was applied to monitor the underground water pollution of a north tailings surrounding， determinated the vicia faba root tip cell micronucleus permillage( MCN‰) and the pollution index ( PI) of 18 tailings surrounding underground water，and processed the F test． The results showed that every point of MCN‰ had significant difference( P ＜0. 01) ， the PI were above two in eight of 18 sampling points，which is of moderate pollution． PI value of eight sampling points was below two，which belongs to slight pollution． PI value of two sampling of the eight sampling were less than two，but the value was 1. 95 approaching two． PI value of the other two sampling points were less than 1. 5，which belongs to the basically no pollution． The water near the tailings were polluted in different degrees． SPSS18. 0 was used to analysis correlation of the MCN‰ and every physicochemical index of the water quality，and the relevance of MCN‰ had significant relation with Cl － ，Na + ，HCO－ 3 ( P ＜0. 05) ．