CO2-3 doping is an effective method to increase the biological activity of nano-hydroxyapatite (n-HA). In the present study, calcium nitrate and trisodium phosphate were chosen as raw materials, with a certain amount of Na2CO3 as a source of CO2-3 ions, to synthesize nano-carbonate hydroxyapatite (n-CHA) slurry by solution precipitation method. The structure and micro-morphology of n-CHA were characterized by transmission electron microscope (TEM), X-ray diffraction (XRD), Fourier transform-infrared spectroscopy (FTIR) and Raman spectroscopy (RS). The results revealed that the synthetic n-HA crystals are acicular in nanometer scale and have a crystal size of 20～30 nm in diameter and 60～80 nm in length, which are similar to natural bone apatite. And the crystallinity of n-CHA crystals decreases to the increment of CO2-3. Samples with more CO23 have composition and structure more similar to the bone apatite. The value of lattice parameters a decreases, value of c increases, and c/a value increases with the increase in the amount of CO2-3, in accordance with crystal cell parameters change rule of type B replacement. In the AB mixed type (substitution OH- and PO3-4) CHA, IR characteristic peak of CO2-3 out-of-plane bending vibration appears at 872 cm-1, meanwhile, the asymmetry flexible vibration band is split into band at 1 454 cm-1 and band at 1 420 cm-1, while weak CO23-peak appears at 1 540 cm-1. CO2-3 Raman peak of symmetric stretching vibration appears at 1 122 cm-1. CO2-3 B-type (substitution PO3-4) peak appeared at 1 071 cm-1. Through the calculation of integral area ratio of PO3-4/CO2-3, OH-/CO2-3, and PO3-4/OH-, low quantity CO2-3 is B-type and high quantity CO2-3 is A-type (substitution OH-). The results show that the synthesized apatite crystals are AB hybrid substitued nano-carbonate hydroxyapatite, however B-type replacement is the main substitute mode. Due to similarity in the shape, size, crystal structure and growth mode, the synthesized apatite crystals can be called a kind of bone-like apatite.