To provide a cellulosic material film having excellent retardation development and small variation of retardation by environmental humidity, an optical compensation film, a polarizing sheet and a liquid crystal display device.

The cellulosic material has two or more substituents having different polarizability anisotropy values and satisfies the formula (1): DSA6/(DSA2+DSA3+DSA6)B6/(DSB2+DSB3+DSB6) wherein A is the substituent having smallest polarizability anisotropy value; B is the substituent having largest polarizability anisotropy value; and DSA2, DSA3, DSA6, DSB2, DSB3 and DSB6 are each the substitution degree of the substituent A or B at the 2, 3 or 6-position of β-glucose ring which is a constitution unit of cellulose.

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