This research concerns itself with the phytochemical substances that can be isolated from the leaves of Thuja occidentalis; chromatographic characteristics of the plant; and the antifungal potentials of Thuja occidentalis. To determine the chemical tests for phytochemical screening of bioactive compounds, the tests that gave qualitative results were employed. Analytical methods that were used included chromatographic methods for instance thin layer chromatography (TLC). It was the procedure that had been used. Algorithms of the fungicidal influence of the substance were tested under the standard approach to examine changes in clinical isolates of fungi. In light of the current results, the special role of T. occidentalis into the process of forming new particular compounds in the antifungal medication therapeutic process is revealed.