Preserving the left colonic artery (LCA) during the laparoscopic radical resection for rectal cancer has been a controversial topic in clinical practice in recent years, and it also has its own development process. Among the pre-laparoscopic era, the inferior mesenteric artery (IMA) was ligatured, LCA was reversed randomly, also, the IMA root nodes (253 nodes) was not cleaned generally. Along with the development of standard operating procedure colorectal cancer, the significant for thedissection of root node has been emphasized. However, due to thesimple procedure, the IMA was ligatured frequently instead of the reversed of LCA which induced a series of clinical question for discussion with the proposer to keep the LCA for colorectal cancer radical prostatectomy. In this study, we enumerated the requirements, key technologies and clinical significance of preserving LCA in laparoscopic radical rectal cancer resection. More importantly, based on my own experience, I believe that preserving LCAmust conducted under the premise of radical resection, and it is easierimplement under laparoscopy. The improvement of this surgical method has many advantages and important clinical significance.