Biomass carbon material derived from dandelion was synthesized by pyrolysing with controlled pseudographtic domain dimension at different temperatures. These domains exhibit larger volume with expanded the average width (La), thickness (Lc) and the average number of graphite layers (n) when increasing the pyrolysing temperature. When tested as anodes in Na-ion battery, the electrochemical results show the biomass carbon displays a superior specific capacity of 361 mAh g−1 at 50 mA g−1. Further research finds increasing La, Lc and n leads to greatly higher plateau capacity below 0.1 V without changing sloping capacity above 0.1 V, indicating the amount of sodium ions de-intercalation between graphite layers is highly sensitive to the dimension of pseudographtic domain. Besides, overlarge dimension of pseudographtic domains are found to hinder the diffusion of Na+ between the graphite layers with obvious capacity loss. This work suggests controlling pseudographtic domain dimension could provide practical reference to pursue higher Na+ storage performance.