ZnO and its composites in various morphologies have been shown promising properties in a wide spectrum of applications. Herein, ZnO nanotubes and ZnO/ZnCo2O4 nanotubes have successfully synthesized by single capillary electrospinning, a heat treatment process was followed to obtain the tubular morphology. The structure of as-prepared nanotubes was confirmed by XRD and EDX analyses. The tubular morphology and its dimensions were identified by SEM and TEM microscopes. The specific surface area and porous structure of ZnO and ZnO/ZnCo2O4 nanotubes were characterized by N2-absorption-desorption isothermal analysis (BET). Excellent improvement in the gas sensing performance has recorded of composite ZnO/ZnCo2O4 nanotubes with n-p heterojunction in comparison with pristine ZnO nanotubes. High response (34) with rapid response (3.2s) and recovery (3.4s) behaviours have clearly observed of as-prepared nanocomposite ZnO/ZnCo2O4 nanotubes toward 100ppm acetone at an optimal temperature of 175°C. The tubular morphology and heterojunction could be the reasons of as-reported improvements of ZnO/ZnCo2O4 nanotubes. The gas sensing properties and mechanism of the as obtain materials in the air and acetone ambient are carefully illustrated and discussed. These finding could provide a potential material for gas sensing application and suggested to test in other fields.