Activity of peroxidase and content of phenol compound in leaves of Alchemilla subcrenata, Achillea asiatica, Taraxacum officinale, Veronica chamaedrys was researched. The information about dynamics of activity of peroxidase and alteration of phenol compound content during around the day in October was got. The dependence of ferment activity and phenol compound substance in leaves of studied plants on temperature was shown. There is a species specificity of the dynamic of the content of phenol compound and peroxidase activity. In the leaf tissues of Alchemilla subcrenata at the fall temperature the activity of loosely-coupled with cell wall peroxidase is increasing, and the content of phenol compound is exhibiting lesser increasing too. Taraxacum officinale and Veronica chamaedrys demonstrated a clear dependence of increase activity of peroxidase with increased content of phenol compounds throughout the day, while the content of phenolic compounds and enzyme activity of Achillea asiatica were in opposite phases.