Abstract: The question of the correct representation of the correlation between the microhardness and the glass transition temperature of glasses is discussed. The type of this correlation depends on the structure of the glasses and can be used to analyze the latter. As an example, the dependence of microhardness on the glass transition temperature of glasses of the phosphorus–selenium system is discussed. It is noted that the dependence of the microhardness on the reduced temperature for glasses with a similar structure is equivalent to the dependence of the microhardness on the temperature of individual glasses. Measurement of the temperature dependences of the microhardness of individual glasses will make it possible to obtain more precise results for discussing the features of their structure in comparison with the dependence of the microhardness on the glass transition temperatures of different glasses, which are however similar in composition.