Abstract: IP Multimedia Subsystem（IMS） brings the networks integration and improves the services providing capability.However，as it deteriorates the IMS-based next generation network security，the research on its vulnerabilities receives extensive attention.The factors of IMS vulnerabilities are drawed by using CVSS and the evaluation mode of vulnerability degree is given based on gray-color theory.The frame based on the gray-color theory is constructed，and the gray degree matrix，three angle weights，functions，gray-color evaluation coefficient，weight matrix，evaluation vector matrix and the evaluation conclusion value are introduced.This model can offer scientific basis for the evaluation of IMS vulnerability degree.

Key words: gray-color theory, network vulnerability, evaluation model

摘要： IP多媒体子系统（IMS）在带来网络融合以及业务提供能力增强的同时，也给基于IMS的下一代网络带来巨大的安全威胁，因而其脆弱性的研究工作受到广泛关注。借鉴了通用脆弱性评分系统（CVSS）的思想提取IMS脆弱性评估的指标，利用灰色理论建立了IMS脆弱性等级评价模型。构建了灰色理论的评价架构，列出了基于灰色理论的评分矩阵、三角权函数、灰色评价系数、权重矩阵、评价向量矩阵和评价结论值，为IMS脆弱性等级评定提供了科学依据。

关键词: 灰色理论, 网络脆弱性, 评价模型