Abstract: The sand pile model can serve as a paradigm for self-organized criticality. This paper reports an experimental study on the sand pile model with semi-boundless collapsed loose slope under inclined plane. Experimental results indicate thatthe self-organized criticalityof a sand pile is related to the granular non-u- niformity, which forthe firsttime experimentally proves the influence of organization principles of the system on the phenomenon of self-organized criticality.