According to the data obtained in HEIFE experiments, in this paper, we analyze the developing process of the nighttime drainage winds and the low level jets. Under normal condition, the characteristics of low level jets in Heihe region are quite similar to those of the low level jets caused purely by nocturnal oscillations. Due to the influence of the Qilianshan Mountain, the nighttime drainage wind occurs along the Gobi slope. When nighttime drainage wind exists before midnight, it has influence on the dev...