This study analyzes the optimal replacement time of Hanwoo cattle using a dynamic programming model. The model determines economically optimum culling time of an individual cow or steer with considering the farmer’s risk aversion and different levels of price. As a result of the analysis, we found that the optimal time is 30-31 months for steer, and that the higher the price, the sooner the replacement. When considering risk aversion, the relative value declines but does not affect the sell decision. The results also indicate that the optimal time to sell a cow is after 44-69 months (or 2-4 parity). The higher price of the cow or the lower price of the calf, the more advantageousit is to quickly replace the cow. Also, the impact of the calf price is bigger than the cow price. As in the case of steer, risk aversion reduces the relative value but does not have a significant effect on the decision.