Abstract: With the repeated moral hazard of longterm contracts aimed at and the agent of time preference taken into account， a threeperiod incentive model was developed and the impact of dynamic inconsistency on longterm contracts was then explored. The results showed that dynamic inconsistency does not change the memorability of longterm contracts， i. e. the high output at the current stage will positively affect the agent's payoff in the later periods; dynamic inconsistency does change the martingales of different periods， and the agent's optimal utility in Period 1 is less than the expected value in Period 2 and Period 3.

Key words: dynamic inconsistency, longterm contract, repeated moral hazard, principalagent issue, martingale