Disclosed herein is cellulose acetate that has excellent heat stability under wet conditions and is capable of reducing the occurrence of end-breakage in a spinning process.

Cellulose acetate satisfying the following formula (1):

[Mg/H.sub.2SO.sub.4]>0,[Ca/H.sub.2SO.sub.4]>0, and

2.70?[Mg/H.sub.2SO.sub.4])/1.62?[Ca/H.sub.2SO.sub.4]?(37.7?[Mg/H.sub.2SO.sub.4])/10.3(1), where the formula (1) represents a relationship between a chemical equivalent ratio of calcium content to residual sulfuric acid content [Ca/H.sub.2SO.sub.4] and a chemical equivalent ratio of magnesium content to residual sulfuric acid content [Mg/H.sub.2SO.sub.4].