Abstract: The port logistics finance practice has been developed rapidly under the port low-carbon transition development. It is very urgent for upgrading port by integrating into a low-carbon port constraint in port logistics pledge loans decision-making theory. In this study, the low-carbon transition port pledge loan interest rate decision model was set up by risk-free arbitrage theory. Based on the option-adjusted spreads principle, the principles of low-carbon control and pledge risk control are proposed. The strong liquidity inventories of low-carbon port logistics pledge loan interest rate decision model was established with the put option reflecting customer default risk-adjusted spread, the pledged goods carbon emissions risk-adjusting spread, and VaR method defining port class of goods as security for loans pledged rate. The important parameter sensitivity analysis showed that: Pledged loan interest rate and pledge rate decline significantly ofter the initial steady, and then recovery, while pledge collateral initial price and the price growth rate of three parameters showed a significant decline in initial, last stable. Carbon discharge rate of treatment costs, financing cost rate, operating cost ratio, risk free rate four parameters showed change in the same direction with the pledge price volatility, collateral value of the rate, change in the opposite direction with pledge loan interest rate and pledge rate. Finally, a port actual case verifies the model feasibility and usability.

Key words: pledge loan interest rate, carbon port, option-adjusted spreads, carbon adjustment spreads, pledge rate