Strategic Information Systems Planning(SISP) has gained considerable interest among researchers and practitioners in recent years Which has instigated various related research. Neverthless, only 24 percent of the projects recommended as a result of SISP are ultimately performed. This statistics raise the questions for the need of SISP. This study provides the framework that may enable SISP to be more effectively utilized by studying factors for consideration from the review of pertinent literature. These factors will then be validated by case studies of domestic companies and by simultaneously inducing key characteristics and solutions of SISP. The result of the study indicate some inconsistency between literal factors and the case study. The factors added through case study were considered to be actual factors of SISP. This study emphasized the role of the senior manager, the quality of the implementation of the state plan, change management and the capability of the planning team. As a key characteristics of domestic companies considered was the general lack of ability to collect and analyze data. In addition, the domestic companies have little consideration of the organizational contingency factors.