In early phase, software engineering technology emphasized software productivity and quality improvement. System user just was concerned about functional requirement and almost omitted the importance of system security. In ISO software quality architecture, security is regarded a sub-characteristic and belonged the functionality. It completely does not meet the e-commerce and internet age. Use cases almost is a standard for describing system functional requirement. However, security does not belong to functional requirement. Security requirement should use a suitable manner for describing and analyzing. In this paper, misuse cases security requirement items (SRI) analysis and specification are discussed. Major missions of SRI, quality characteristics of SRI and SRI quality factors collection are studied. Based on SRI quality measurement model, the paper proposes the SRI Quality Improvement Procedure (SRIQIP). Applying SRIQIP, quality defects of security requirement can be identified. With quality improvement operation, security requirement quality can be enhanced continuously and system security can be increased.