The last decade has shown that object-oriented concept by itself is not that powerful to cope with the rapidly changing requirements of on-going applications. Component based system achieves flexibility by clearly separating the stable parts of systems (i.e. components) form the specification of their composition. In order to realize the reuse of components effectively in component based software development, it is required to measure the reusability of components. However, due to the black-box nature of components where the source of these components are not available, it is difficult to use conventional metrics in components based development as these metrics require analysis of source codes. In this research, we adopt FUZZY Logic based approach to estimate the reusability of components. Several factors of reusability are taken into account.