<p>Based on data from Chinese A-share listed companies between 2000 and 2023, this paper empirically examines corporate capital structure decisions and adjustments under capital market regulation using both a static capital structure model and a partial dynamic adjustment model. The study finds that enterprises with equity-financing qualifications tend to maintain a capital structure characterized by a low debt-to-asset ratio. However, during periods of tight monetary policy, these enterprises are more inclined to choose debt financing, which increases their leverage ratio. This capital structure decision is driven by cost differences between equity and debt financing under market regulatory rules. Enterprises with equity-financing qualifications have a more flexible range of financing strategies. Benefiting from the cost advantages provided by the equity market, these enterprises often exhibit equity-financing stickiness, thereby reducing the speed at which they adjust their capital structure. This paper reveals the strong preference of Chinese enterprises for equity financing and explains the low leverage ratios from the perspective of financing costs. It offers both theoretical and practical support for the regulation of capital market financing in emerging economies, including China.</p>