A sealing member and a toilet flange assembly are disclosed. The sealing member is made of an elastic material, and includes an upper ring portion, a connecting ring portion and a lower ring portion that are connected in sequence from top to bottom. The upper ring portion is fitted on a flange member. Upper and lower ends of the connecting ring portion are connected to the upper ring portion and the lower ring portion, respectively. An inner wall of the connecting ring portion is connected with a toilet drain pipe. The lower ring portion has a diameter less than that of the upper ring portion. An outer wall of the lower ring portion is connected with a ground drain pipe. The toilet flange assembly can solve the problem of fitting between toilet drain pipes of different diameters and ground drain pipes.