Abstract: The reform of rural collective property rights transcends mere systemic adjustments; it's a crucial catalyst for county-level economic growth. This study leverages the latest round of these reforms as a quasi-natural experiment, analyzing their impact on economic growth in 1, 911 counties from 2010 to 2019. The research delves into the underlying mechanisms and varying effects of this impact. Results show a substantial enhancement in counties' economic development due to these reforms. Specifically, they boost economic growth by elevating production efficiency, encouraging industrial concentration, and attracting capital. Notably, in eastern regions and more marketized counties, the economic boost from these reforms is more evident. To maximize the potential of rural collective economies, increasing the reforms' inclusiveness and adaptability is recommended. Such measures will energize rural collective economic organizations, contributing to superior economic growth at the county level.