The study of four years straw mulching and white clover intercropping in a tea plantation in subtropical hilly region showed that the soil temperature in the plantation presented a distinct dynamic temporal-spatial variation and hysteresis, which was greatly accorded with the fittest temperature of tea growth. Straw mulching and white clover intercropping altered the nature of soil thermal exchanging layer (soil surface), decreased daily temperature difference, enhanced the temperature stability in the same soil layer, and had duplex effects of lowering temperature when it went up and increasing and keeping temperature when it went down. The effectiveness was in the order of white clover intercropping > straw mulching > control, 13:00 > 19:00 >7:00,and lowering temperature > increasing and keeping temperature, and decreased with soil depth. Straw mulching and white clover intercropping adjusted the switching point of the temporal-spatial variation of soil temperature, and evidently decreased the emergence of harmful high temperature. During the period of continual high temperature, these measures markedly lowered soil temperature, and effectively shortened the duration of this period.