Objective To summarize the assessment methods of anal function after low/ultralow rectal anastomosis in patients with rectal cancer. Methods Domestic and international publications on the study of evaluation of anal function after low/ultralow rectal anastomosis in patients with rectal cancer were collected and reviewed. Results Anal function of patients with rectal cancer was usually evaluated by feeling of discharge, continence, perceptual function of rectum, defecate frequency, and defecation time, anal manometry and three-dimensional vector manometry were used as well. Recovery of anal function in patients with rectal cancer after low/ultralow rectal anastomosis depended on the integrity of anal canal, length of remaining rectum, level of anastomosis, and integrity of mucosa. Conclusions Subjective assessment methods and auxiliary measuring instruments are the common means to evaluate the rectal-anal function. Subjective assessment method is simple and direct, but its accuracy is low; Auxiliary measuring instruments have high accuracy, while their examination costs are high and that of costs are not popular, the new assessment methods are needed for further research.