Interest subsidies to banks and enterprises are two types of green financial incentives that government supports enterprises in their low-carbon transition in practice. This paper investigates green loan pricing decisions of a bank in perfectly competitive and monopolistic financial market and a capital-constrained enterprise's production and carbon emission reduction decisions. Then, this paper compares the economic-environmental values contributed by green credit under two incentive policies. The research finds that: (1) The enterprise's emission-reduction technology, initial capital, and carbon asset levels will jointly affect the economic-environmental value of green credit. Moreover, there exist parameter regions in which green credit results in poisitive economic and environmental values. (2) When the enterprise borrows without default risk, the two interest subsidies are equivalent from economic and environmental perspectives. (3) When the enterprise borrows with default risk and the bank is in a perfectly competitive financial market, subsidizing the bank is superior to subsidizing the borrower on the sides of economic and environmental perspectives; the converse holds when the bank is in a monopolistic financial market.