This study focuses on the investment e ciency of renewable energy enterprises and how they respond to government green scal policies. It complements previous research that only examines corporate investment e ciency from government subsidies or tax incentives. Moreover, we extend the impact of green scal policies on the investment ine ciency of renewable energy enterprises from the perspective of property heterogeneity. We choose nancial data of 158 renewable energy enterprises for both state-owned (SOEs) and private (Non-SOEs) listed on the Shanghai and Shenzhen Stock Exchange from 2010-2018 and use the Richardson model to measure the investment e ciency. The xed-effect panel model is applied to explore the impact of green scal policies on the investment e ciency of renewable energy enterprises. The results show that, in general, green nancial subsidies aggravate over-investment, especially for SOEs, while green tax incentives alleviate under-investment considerably, especially for Non-SOEs. We also nd ine cient investment pervasive in China, among which the over-investment problem more serious than underinvestment. But for the Non-SOEs, under-investment is more predominant. Finally, we propose that government subsidies for SOEs should be constrained and supervised, while more exible tax incentives for Non-SOEs should be advocated.