A facile one-step wet chemical method for preparing SnO2@OCNTs composite was described in this paper. The formation of composite is dried by the capillary force and electrostatic interaction. The results reveal that the Open-tips CNTs (OCNTs) are filled with ultrafine SnO2 nanoparticles (4–6nm) and with a few SnO2 nanoparticles on the outside surface. The composite delivers a capacity of 848 mAh g−1 (based on the mass of composite) in the first cycle and keeps 83.5% of the original capacity after 300 cycles at the current density of 70mAg−1. Furthermore, the composite still releases a capacity of 398 mAh g−1 at the current density of 3000mAg−1.