Abstract: Thew eathered co lumnar strom atolites are w ide ly d istributed in the study area and have a strong rock streng th and the reg ional variability. The rock strength is the important factor for slope stability. E va luation of slope stability needs to analyze the field test data as stochastic variab le to obtain the reliable ind icators of rock strength. Th is paper bases on the statistica l analysis of the po int load test data of medium w eathered co lumnar stromato lites limestone in study area and uses the fitt ing of probab ility density function w ith the x 2 check m ethod. It draw s the conc lusion that probab ility d istribut ion fo rm of the rock streng th. The compressive strength and tensile strength are subject to the lognormal d istribution. This result is further combined w ith the fitt ing results o f the streng th o f sim ilar rock lithology. A a resu l,t th is paper estab lishes the probab ility d istribution function for po int load test strength o f medium w eathered co lumnar strom ato lites limestone in the study area. The limestone po int load strength w as de duced w ith Bayes estimat ion. The predict ive value of rock strength is obtained. The re lative error is less and sam pling confidence is over 70%. The tensile streng th w as 2. 29MPa, the compressive strength w as 72. 42MPa. The method for the rock streng th w as est imated to be effective, the va lues obtained w ith the method had the important practical significance to eva luate slope stab ility andmanage the slope.