1. Applied Technology College of Jilin University��Changchun 130012��China; 2. College of Geo-exploration Science and Technology��Jilin University��Changchun 130026��China

It is critical for the stability evaluation of tunnel to obtain accurate tunnel rock structure plane geo- metric information�� In this paper��the study area is located in the Moon Lake of Changchun��rock mechanics prac- tice base tunnel of Jilin University�� According to the basic principle of measuring work “scattered after the first control” ��we applied reflectorless total station to make control measurement of rock tunnel��and carried on traverse survey of total station prism mode and rock structure plane control points measurement using polar coordinate meth- od of total station without prism mode in each traverse point�� Through the comparison and analysis of control point coordinate data of the same structure plane on the same and different station��the authors discussed the tolerance of the angle between reflectless total station measuring direction and structure plane�� The results shows that the angle between reflectless total station measuring direction and structure plane is greater than 30 degrees is one of the nec- essary conditions for obtaining accurate rock target control point coordinate in the tunnel control measurement��