在模拟人体生理条件下，利用荧光、紫外-可见吸收和同步荧光光谱法研究了水溶性壳聚糖(CS)及两种壳聚糖稀土配合物(CS-La和CS-Dy)与牛血清白蛋白(BSA)的相互作用. 紫外吸收光谱分析表明，CS, CS-La和CS-Dy相互作用的最大吸收峰强度都增加. 用Stern-Volmer方程分别对荧光光谱的实验数据进行分析，发现CS-La对BSA的荧光猝灭作用属于静态荧光猝灭，反应生成新的复合物. 而CS和CS-Dy对BSA的荧光猝灭作用有静态荧光猝灭和动态猝灭，发生了分子内的非辐射能量转移. 求得三种物质在室温和体温的情况下与BSA相互作用过程的结合常数KA [291 K, CS-BSA: 1.807′104 L/(g·s), CS-La-BSA: 3.065′104 L/(g·s), CS-Dy-BSA: 2.193′104 L/(g·s); 310 K, CS-BSA: 2.665′104 L/(g·s), CS-La-BSA: 2.022′104 L/(g·s), CS-Dy-BSA: 7.246′104 L/(g·s)]和相关热力学参数；确定了CS和CS-Dy与BSA之间的主要作用力是静电和疏水作用力，而CS-La与BSA之间的作用力主要为范德华力和氢键等作用力. 同步荧光光谱表明，CS, CS-La和CS-Dy均对牛血清白蛋白的构象和所处的微环境产生影响.

The interaction between chitosan (CS), its complexes CS-La and CS-Dy, and bovine serum albumin (BSA) in vitro under simulative physiological conditions was studied by fluorescence, ultraviolet-visible absorption and synchronous fluorescence spectrometry. The results showed that CS, CS-La, CS-Dy had strong effects on quenching of the fluorescence launching and enhanced the UV absorption spectra of BSA. After the fluorescence quenching, the obtained data were analyzed by Stern-Volmer equation, the results indicated that the reactions between BSA and CS, CS-La and CS-Dy generated new complexes. The quenching belonged to static fluorescence quenching, with non-radiation energy transfer happening within single molecule, but the static and dynamic quenching coexisted in the reactions between CS and CS-Dy and BSA. The binding constant KA (291 K, CS-BSA: 1.807′104 [L/(g·s)], CS-La-BSA: 3.065′104 [L/(g·s)], CS-Dy-BSA: 2.193′104 [L/(g·s)]; 310 K, CS-BSA: 2.665′104 [L/(g·s)], CS-La-BSA: 2.022′104 [L/(g·s)], CS-Dy-BSA: 7.246′104 [L/(g·s)] and thermodynamics parameters (DH, DS, DG) were calculated, respectively according to the equation of fluorescence spectrometry at different temperatures. Based on thermodynamic data, the main reactions between CS and CS-Dy and BSA were electrostatic and hydrophobic forces, but those between CS-La and BSA van der Waals and hydrogen bond forces. The effects of CS, CS-La and CS-Dy on the conformation of BSA shown by synchronous fluorescence spectrometry indicated that they changed the micro-environment and conformation of BSA molecules.