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 Na2 CO3 as a source of CO2 -3 ions ,to synthesize nano-carbonate hydroxyapatite (n-CHA) slurry by solution precipitation method .The structure and mi-cro-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 re-placement .In the AB mixed type (substitution OH - and PO3 -4 ) CHA ,IR characteristic peak of CO2 -3 out-of-plane bending vi-bration 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 re-placement is the main substitute mode .Due to similarity in the shape ,size ,crystal structure and grow th mode ,the synthesized apatite crystals can be called a kind of bone-like apatite .%CO2-3掺杂是提高纳米羟基磷灰石（n-HA）生物活性的有效方法之一。以 Ca（NO3）2·4H2O 和Na3PO4·12H2O为主要原料，Na2CO3作为CO2-3来源，合成纳米碳羟基磷灰石（n-CHA）晶体。采用TEM ， XRD ，FTIR ，RS对合成晶体形貌和结构进行表征。结果表明：合成的n-HA晶体长度约为60～80 nm ，宽度在20～30 nm之间，形状为针状，具有良好的结晶度，与自然骨磷灰石形貌相似；n-CHA晶体随CO2-3掺入量的增加，结晶度降低；合成的 n-CHA晶体的晶胞参数 a值随着CO2-3加入量的增大不断收缩，但 c值增大，参数比c/a值增大，符合B型取代（取代PO3-4）的晶胞参数变化规律。红外谱图中，872 cm -1附近出现AB混合型取代（同时取代O H -，PO3-4）的CO2-3面外弯曲振动特征红外峰，同时CO2-3的不对称伸缩振动红外峰在1454和1420 cm -1附近出现分裂峰，1540 cm -1附近出现弱CO2-3峰；1122 cm -1附近出现CO2-3对称伸缩振动拉曼峰，1071 cm -1附近出现CO2-3的B型替代特征拉曼峰，通过计算PO3-4，CO2-3，O H -拉曼峰的积分面积比PO3-4/CO2-3，O H -/CO23，PO3-4/O H -，表明CO2-3在替换时，先以B型为主，随着CO2-3掺入量的增加，发生A型替代（取代O H -）。实验结果表明，合成的磷灰石晶体为B型取代（取代PO3-4）为主的AB混合型取代的 n-CHA。与人骨磷灰石晶体在形态、尺寸、晶体结构和生长方式上具有相似性，可称为类骨磷灰石。
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