Changes in collagen mass in rats were studied under the conditions of local cold injuries. A method for quantitative determination of collagen in the dermis was developed and applied for the first time. Cold injury was replicated in mongrel male and female rats weighing 180–200 grams by applying a metal weight 2.5 cm in diameter, cooled in liquid nitrogen, to depilated skin on the back. A statistically significant decrease in collagen content was recorded in rats on day 3 after cold damage. Starting with the 14th day after the cold injury, an increase in collagen content was observed due to the restored activity of fibroblasts. By the 21st day, collagen content continued increasing, but full recovery was not observed.