Ambrosia artemisiifolia L. is an aggressive weed species whose predominantly allergenic properties are studied by various possibilities of prognostication and suppression. Analyzing the soil seed bank can help to better understand the dynamics of the Ambrosia population, which results in more effective suppression of this species. In order to get accurate data on the dynamics of Ambrosia initiation, it is necessary to determine the percentage of dormant, non-dormant (germinating) and dead seed in the seed population. This can be achieved with different non-destructive and destructive methods which can determine viability of the seed. The aim of this master’s thesis was to: I) compare the results of validation of the seeds viability with three destructive methods: germination test, tetrazolium test and crush test; and II) to determine whether differences between the tetrazolium and the crush test were differences in reliability as well as the possibility of repeatability. The results of research indicate that there is no significant difference in the viability of the Ambrosia seed between tetrazolium test, crush test and germination test supplemented with the tetrazolium test. All three methods identified about 90% of the viability seed. Germination test showed 77% germinating seeds, so it is necessary to supplement it with tetrazolium or crush test to determine viability of the seeds. Visual perception of the same researcher of the first grade rating of the same evaluator in the time lag of 60 minutes on the second grade, is not significantly changed. The results of the comparison of the first and second evaluations of both researcher indicate that they have similarly evaluated seed viability, which confirms the reliability and repeatability of the TTC test. Crush test also gives objective results of Ambrosia seed viability and there is no significant difference in estimation of it.