Cellulose ester and production method thereof

A cellulose ester having a total degree of substitution at the 2-, 3-, and 6-positions of 2.900 to 2.965, a total degree of substitution at the 2- and 3-positions of not less than 1.97, and a half height width of a distribution in degree of substitution of not more than 0.07,

• wherein said cellulose ester is a cellulose C2-6acyl ester, and
• wherein the half height width is determined by converting a retention time of the cellulose ester, said retention time being measured by high-performance liquid chromatography (HPLC), into a degree of substitution to obtain an uncorrected half height width, and by further converting the uncorrected half height width to a corrected half height width in accordance with the following equation:
• Z=(X2−Y2)1/2
• wherein Z is the corrected half height width, X is the uncorrected half height width determined by HPLC, and Y is the half height width for a cellulose ester having a degree of substitution of 3.0 determined by HPLC.