To provide a cellulose acylate film that has a high dimension stability and retardation stability against the change in humidity, and an optical film and liquid crystal display device using the film.

A cellulose acylate film is manufactured by a casting method comprising a casting step for casting a cellulose acylate dope composition comprising a (meth)acrylate monomer represented by general formula (I), a photopolymerization initiator, and a cellulose acylate, and a step for light irradiation (in the formula, R is H or CH3; m is an integer of 1-20; n is an integer of 2-50; X is a n-valent organic group having a hydrocarbon ring structure; and Y is a single bond or an (m+1) valent connecting group). This cellulose acylate film is used for various optical films and liquid crystal devices.