This paper examines China's economic growth since the groundbreaking reforms of 1978, focusing on the factors that have propelled the nation to become the world's second-largest economy and the challenges it now faces in sustaining its growth. The study integrates historical insights with modern macroeconomic analysis, utilizing frameworks like the Solow model and growth accounting to assess the contributions of physical capital, labor, and human capital. The paper aims to illuminate both the successes that have driven China's remarkable transformation and the potential pitfalls that could shape its future economic trajectory.