Abstract: The definitions of both the chamber temperature stabilization and the test sample temperature stabilization in temperature tests are introduced. The definitions of the test sample temperature stabilization in civilian and military standards and their differences are analyzed. The methods for determining the temperature stabilization time are discussed, especially, the pros and cons of three commonly-used methods and their applications. The concept of the temperature maintaining time and its composition in high and low temperature operation tests are introduced. The related specifications in GJB 150 and MIL-STD-810 serial standards are discussed. Finally, some suggestions are made to determine the test sample's temperature stabilization time.