Abstract-Nowadays a lot of various test generation tools are developed and applied to create tests for both software applications and hardware designs. Taking into account the size and complexity of modern projects, there is an urgent need for "smart" tools that would help maximize test coverage and keep the required effort and time to a minimum. Despite the fact that each project is unique in some sense, there is a set of common generation techniques that are applied in a wide range of projects (random tests, combinatorial tests, tests for corner cases, etc). In addition, projects belonging to specific domains tend to share similar test cases or use similar heuristics to generate them. A natural way to improve the quality of testing is to make the most of the experience gained working on different projects or performing testing at different stages of the same project. To achieve this goal, a knowledgebase holding information relevant to test generation would be of a great help. This would facilitate reuse of test cases and generation algorithms and would allow sharing knowledge of "interesting" situations that can occur in a system under test. The paper proposes a concept of a knowledgebase for test generation that can be used in a wide range of test generation tools. At ISPRAS, it is applied in test program generation tools that create test programs for microprocessors. The knowledgebase is designed to store information on widely used test generation techniques and test situations that can occur in a microprocessor design under verification.