The temperature characteristics of two-beam coupling in photorefractive crystal was discussed by using the one-carrier and one-level band-conduction model. The effect of physical parameters on the temperature characteristics was analyzed generally. In this paper, the concept of thermosenseless range has been put forward. If a crystal operates in this range, the optimum results of high efficiency, small thermonoise and small thermodrift of operation point can be obtained. The relationship between physical parameter and the location and extent of the range has been given, the method to amend experiment has been suggested.