The method of sample test was taken, in which infrared antireflective films samples were deposited on Ge substrate, and samples were tested in tropical rainforest environment in Xishuangbanna. By using FT-IR spectrometer and SEM, the characteristics of samples before and after the experiment was analyzed. The stability of samples in tropical rainforest environment was studied. The experiment results show that the corrosion and expansion from micro defect sites in the films are one of the main influence fact...