An all cellulose-based composite was produced by applying cellulose diacetate (CDA) and electrospun cellulose fibers (ECFs) as a matrix and reinforcing fibers, respectively. The ECFs were prepared by electrospinning CDA followed by alkali treatment. The alkali treatment of the electrospun CDA fibers removes acetyl groups and creates new crystalline domains similar to cellulose fibers, which may result in increased mechanical properties. The physical properties of ECFs are highly correlated with the acetyl content. The mechanical properties of the CDA/ECF composites were evaluated by measuring the tensile strength and Young's modulus as a function of the hydrolysis time. The results showed that the integration of the CDA matrix with 15% weight/weight (w/w) ECF7, which was alkali-treated for 7 h, was optimal, resulting in an improved tensile strength and Young's modulus by factors of 1.7 and 2.2, respectively. This study demonstrates that the increased mechanical properties are attributed to the reinforcement of ECFs as well as good interfacial adhesion. (C) 2013 Elsevier Ltd. All rights reserved.