People’s understanding of lumbar spinal stenosis has become more and more comprehensive and reasonable, however, there are still many controversies about the concepts of " central lumbar canal” and " lateral lumbar spinal canal”, and there is no unified standard at present. In this paper, we redefine and differentiate the two concepts. We believe that some kinds of central canal stenosis caused by bilateral recess stenosis can be completely solved by bilateral percutaneous endoscopic transforaminal discectomy. At the same time, the concept of " lumbar lateral recess” is ambiguous. We redefine it as " lateral lumbar spinal canal” and propose " West China Hospital classification” to guide surgical decision-making, which has been widely recognized and applied.