以输运理论的P3近似为基础，推导了空间分辨漫反射的一阶散射参量灵敏度的解析表示，并进行了数值分析，比较了散射参量对P3近似和漫射近似漫反射的影响.结果表明：在距光源两个输运平均自由程以内，该灵敏度与相应于漫射近似的灵敏度差别较为明显；距离光源约四个输运平均自由程附近，该灵敏度等于零，并且与光源之距与相应于漫射近似情况也不同；该灵敏度等于零的源-探测器之距随组织散射参量增大而减小，且组织吸收越弱这种变化越明显.本研究对于在一阶散射参量灵敏度等于零处，利用漫反射获取组织吸收信息具有重要的理论意义.

The sensitivity expression of spatial-resolved diffuse reflectance to first-order scattering parameter was derived and numerically analyzed based on the P3 approximation of transport theory,and the influence of scattering parameter on the P3 approximation and diffusion approximation reflectance were also compared.The results show that:the sensitivity is distinct with that of the diffusion approximation in the region of about two transport mean free paths;the sensitivity to scattering parameter equals zero at the distance about four transport mean free paths which differs with the diffusion approximation;the optimum source-detector distance decreases with the increase of the scattering coefficient,and this change becomes more obvious with lower absorption.The research has theoretical significance to obtain absorption information of tissue with diffuse reflectance at the optimum source-detector distance.