This invention provides fibers made from a thermoplastic cellulose ester composition, which can maintain excellent mechanical properties still after high temperature dyeing treatment, especially suitable as fibers mixed with polyester fibers or as fabrics woven or knitted together with polyester fibers, and also provides the thermoplastic cellulose ester composition constituting the fibers. For example, this invention provides a thermoplastic cellulose ester composition containing at least 70 to 95 wt % of a cellulose fatty acid mixed ester with an average substitution degree of 2.4 to 2.8, 5 to 25 wt % of a plasticizer and 1 to 10 wt % of a cellulose acetate with an average substitution degree of 2.3 to 2.6, and also provides fibers made from the thermoplastic cellulose ester composition.