Abstract: The point load strength test is implemented on the fresh rock picked up from the scene.The experimental results is analyzed detailedly based on the data of the size of the test block.The results of the research show that,The length of the rock is almost has no effect on the result of the research,so,the thickness and width are the main factors influencing the point load strength.To be specific,the best test results can be obtained under the conditions of the with in 50~100 milliammeter and the thickness in 30~50 milliammeter.Then,the strength of point load changes along with the changes of the size.On the whole,the research results in this paper can provide some refence for the further research in irregular rock point load strength.

Key words: Irregular rock, Point load, Experiment of strength