To investigate the pore structural effects on the electrochemical performance of ordered mesoporous carbons (OMCs) as anode materials for sodium ion battery (SIB), we prepared OMCs with various rod lengths from 350 nm to 1300 nm, and different pore sizes from 4.7 nm to 6.5 nm by changing the hydrochloric acid concentration in the P123/silica/glycerol composite system. The reversible capacities of OMCs with the average length of 350 nm, 700 nm, 900 nm and 1300 nm were 214 mA h g(-1), 217.4 mA h g(-1), 232.6 mA h g(-1), and 228.9 mA h g(-1) at 50 mA g(-1), respectively. Furthermore, the OMC with largest pore size (6.5 nm) presented the highest capacity and even remained 100 mA h g(-1) after 1000 cycles at 500 mA g(-1) with the coulombic efficiency of nearly 100%. We confirmed that the carbon with ordered mesostructure, bigger pore size and shorter length of pore channel exhibited higher capacity. The results propose an effective direction and strategy for designing mesoporous materials to enhance the electrochemical performance of SIB. (C) 2016 Elsevier Ltd. All rights reserved.