In this thesis, new methods to handle reconvergent fanout and feed-back during behavioral level test generation are proposed. These methods have been implemented - into a previously developed automatic test generator. The improved test generator was tested on five behavioral circuit models. For circuits with the reconvergent fanout situation, the improved test generator can generate tests completely automatically. For circuits with feed-back, user assistance in a circuit initialization step is required. Some suggestions for future development for the test generator are discussed. Examples on how to use the improved test generator are presented.