The conventional triaxial test on cylinderical specimens is the most important one in laboratory test for the determination of the strength of rock. With this method, only one point of the failure envelope can be obtained per specimen. In order to save time and reduce test costs. Prof. Kovari has developed the continuous failure state triaxial test abbreviated to CFS triaxial test. Thus, in principle, it is possible to obtain the failure envelope with one specimen. But there is still an important problem to be solved for this new method. That is how to detemine the controlling parameter V/E to make the stress-confining pressure curve correspond closely to failure envelope of the rock.In this paper we present the tracing method to solve this problem. First of all, it is justifiable that distribution of peak points of various stress strain curves with different confining pressure can be treated as a straight line approximately. Then, according to a known point which will be given by uniaxial or triaxial test before GFS test, we can trace this line to obtain the points on the line close to the relevant peak points. CFS triaxial test which is executed with the traoing method exhibits failure envelope obtained by a series of conventional tests. Many tests show that the tracing method is an efficient and simple method.