Seeds of Paulownia tomentosa cannot germi-nate without light. As is shown in Table 1, very few of seeds germinated when kept in darkness, while they showed good germination in diffused light. Ten minutes breakage of dark treatment did not show any effect. The experiment was carried on in glass incubator kept at 25°C. For each plot were supplied 4 Petri dishes containing 50 sterilized seeds, and 1% agar was used as germinating bed.