中文摘要：

基于卡尔曼滤波方法，开发了漂移室径迹拟合算法。在软件中仔细处理多次散射、能量损失等物质效应，处理磁场不均匀性的影响，考虑重力下垂、单丝空间分辨和其他刻度因素。描述了漂移室径迹拟合软件包的设计实现、主要算法，并用模拟样本对算法及其相关参数进行了优化。对其性能进行的研究表明，拟合结果的各种分布是合理的，本软件对径迹参数、误差矩阵以及动量分辨率都有所改善，对低动量的强子径迹更为明显，从而对BESⅢ物理结果有较为显著的影响。

英文摘要：

Track fitting based on Kalman Filter technique has been developed for BESⅢ. The design and implementation of the algorithm are described with handling of material effects such as multiple scattering and energy loss, treatments of non-uniform magnetic field, wire sagita, and calibration issues. The performances of the algorithm and some physics checking are presented with simulation samples.