Labor-management relations not only serve as a comprehensive measure for evaluating a firm's level of human resource management but are also closely related to corporate productivity and competitiveness. Most world-class excellent companies maintain cooperative labor-management relations, and Korean firms have also recognized since the June 29 Declaration of 1987 that labor-management relations are the most critical factor in enhancing corporate competitiveness. However, there has been virtually no research capable of assessing the level of labor-management relations within a firm, and the multitude of factors influencing labor-management relations has made it difficult to evaluate and compare the stability of labor-management relations across firms. This paper proposes a method for assessing the level of labor-management relations by utilizing correlation analysis between organizational commitment to the company (company commitment) and organizational commitment to the labor union (union commitment) among employees in firms where labor unions are established. Company commitment and union commitment not only share some of their determinants, but from the company's perspective, labor-management relations can only be managed through organizational management and personnel management, making this approach highly applicable at the practical level. The results showed that higher levels of satisfaction with personnel and organizational management were associated with higher company commitment and lower union commitment. Furthermore, a higher positive correlation between company commitment and union commitment indicated more stable labor-management relations, while a higher negative correlation indicated more unstable relations. Synthesizing the results of this study, the stability of labor-management relations can be evaluated through correlation analysis of company commitment and union commitment measured via attitudinal surveys. In the case of Korean firms, the negative correlation coefficient suggests that adversarial labor-management relations are more prevalent than cooperative ones.