Abstract: High-quality Party building represents the latest theoretical development and practical innovation in the Sinicization and modernization of Marxist theories of party building. At its core, it places the Party's political construction at the forefront and relies on the Party's capacity for self-reform to systematically advance Party building in the new era through greater institutionalization, standardization, and digitalization. In doing so, it transforms the Party's political and organizational strengths into governance capacity and momentum for high-quality development. With the launch of the 15th Five-Year Plan, China's pursuit of high-quality economic and social development faces an increasingly complex environment characterized by structural challenges and growing uncertainties. Under these circumstances, it is essential to fully leverage the leading role of high-quality Party building. Priority should be given to strengthening the "four capabilities" to consolidate the institutional foundation, while further improving Party conduct to enhance policy implementation and governance effectiveness. By effectively transforming the Party's distinctive political strengths into a sustained driving force for high-quality development, China can ensure that its modernization continues to advance steadily along the path of socialism with Chinese characteristics.