To obtain a cellulosic film having an excellent planarity, slight changes in inplane retardation (Re) and retardation (Rth) in the thickness direction by humidity variation and an excellent productivity, a retardation film using the same, an optical compensation film and a polarizing plate and to provide an image display apparatus.

The cellulosic composition comprises a cellulosic containing a 5-30C aliphatic acyl group (A) and a 2-4C aliphatic acyl group (B) in which the substitution degree of the aliphatic acyl group (A) satisfies a specific range.