In this study, carboxymethyl cellulose (CMC) used as matrix, while halloysite nanotube (HNT) used as nanofiller to produce bio-nanocomposite films via solvent casting method. The effect of sodium dodecyl sulfate (SDS) on tensile properties and morphology study of CMC/HNT bio-nanocomposite films have been investigated. The results showed that the mechanical properties of treated CMC/HNT bio-nanocomposite films using SDS enhanced the tensile strength, elongation at break and modulus of elasticity compared to untreated CMC/HNT bio-nanocomposites. Besides, the tensile fracture surface of treated bio-nanocomposites demonstrated by field emission scanning electron micrograph (FESEM) indicates that the presence of SDS improved the interfacial interaction between CMC matrix and treated HNT nanofiller.