The environment for pig production should be controlled according to a criterion based on the pig"s thermoregulartory behavior. Quantifying the pig"s thermoregulatroy behavior was needed to prepare a criterion based on the pig"s thermoregulatory behavior. Therefore, this study was conducted to quantify the pig"s thermoregulatory behavior. The raw images were acquired according to the pig"s thermoregulatory behavior and they were processed to binary images. The mean deviations of x and y coordinates of pig"s images in a binary image were computed and they were multiplied. The values computed in this manner showed very wide differences according to the pig"s thermoregulatory behavior. Therefore, the image processing and mean deviation can be certainly used as a method for classifying the pig"s thermoregulatory behavior.