Heat preservation and energy saving experiment using aluminized thermal screens in greenhouse was conducted. The temperatures inside greenhouse both with and without thermal screens were measured based on experiment. The experimental result showed that air temperature inside greenhouse under aluminized thermal screens can be improved by 3～5℃, and the air temperature at 40 cm above the screen was 8.8℃ higher than that at 40 cm under the screen. According to calulated results of the heating load of the greenhouse and the overall heat transfer coefficient of the roof with and without thermal screens, the average energy saving efficiency reached about 37%, which reveals excellent thermal performance of aluminized thermal sreens.