1. To protect the global ecological environment and prevent threats to human safety and property, nations around the world have invested heavily in ecological restoration programmes. However, we don’t know whether these investments have been repaid by the resultant benefits.

2. To answer this question, we developed an improved method of quantifying costs and benefits that accounts for more of the costs associated with ecological restoration, thereby letting us calculate the net benefit.

3. To demonstrate this method, we analysed the Grain for Green Program, which is the world’s largest ecological restoration program. We found that the increase in net benefits amounted to a total of 530.1×10⁹ RMB·yr^-1 in 2017. However, 11 of China’s 25 provinces have incurred net losses due to high cost increases and low increases in benefits under the GGP.

4. Synthesis and applications. Because compensation payments to farmers and herders whose livelihoods were disrupted by implementation of the Grain for Green Program only accounted for 0.8% of the programme’s cost, improving compensation payments will be essential to its success. Assessing GGP the largest ecological restoration program in the world will provide guidance for ecological protection and restoration policies around the world.

1. To protect the global ecological environment and prevent threats to human safety and property, nations around the world have invested heavily in ecological restoration programmes. However, we don’t know whether these investments have been repaid by the resultant benefits.

2. To answer this question, we developed an improved method of quantifying costs and benefits that accounts for more of the costs associated with ecological restoration, thereby letting us calculate the net benefit.

3. To demonstrate this method, we analysed the Grain for Green Program, which is the world’s largest ecological restoration program. We found that the increase in net benefits amounted to a total of 530.1×10⁹ RMB·yr^-1 in 2017. However, 11 of China’s 25 provinces have incurred net losses due to high cost increases and low increases in benefits under the GGP.

4. Synthesis and applications. Because compensation payments to farmers and herders whose livelihoods were disrupted by implementation of the Grain for Green Program only accounted for 0.8% of the programme’s cost, improving compensation payments will be essential to its success. Assessing GGP the largest ecological restoration program in the world will provide guidance for ecological protection and restoration policies around the world.

The data of value of ecosystem services of Grain for Green Program are collected from monitoring sites under the authority of the Chinese Academy of Sciencesand China’s State Forestry Administration, and data of costs, value of products, compensation, area are from related statistical yearbooks.