Abstract: China’s traditional informal system of“relationship contract trust”has contributed to the widespread dependence of enterprises on large customers, which is not conductive to their long-term development in the era of rapid development of the digit economy. Based on the samples of non-financial listed companies in China from 2007 to 2019, this paper analyzes the relationship between the digital transformation and the dependence on large customers. The results show that the digital transformation can effectively reduce customer concentration and then reduce their dependence on large customers. The results still hold after the robustness tests, such asthe parallel trend and placebo tests, changing the variable measurement indicatorsand the instrumental variables. In terms of the mechanisms of action, the improvement of corporate competitiveness and information transparency are two important mechanisms of the digital transformation affecting the customer concentration. Further examination of the cross-sectional differences reveals that the negative effect of digital transformation on the customer concentration is more significant among the firms with stronger management capabilities, higher technologies, higher market shares and higher levels of external digitization. The above findings can not only enrich the study of the influencing factors of customer concentration and provide empirical evidences for enterprises to reduce their dependence on large customers,but also provide a decision-making basis for local governments to formulate differentiated policies to promote enterprises’ digital transformation.

Key words: digital transformation, customer concentration, corporate competitiveness, information transparency