This study analyze the determinant factors that affect the purchase of crop insurance, using the survey data of 374 farmers. In the estimated result, farmers are found to buy insurance in areas where strong winds and heavy rains occur frequently. The risk of production reduction faced by individual farmers is the hidden information that is difficult for insurance companies to acquire, which makes it harder to be reflected in insurance premiums. Analytical results suggest that insurance premiums are likely to be underestimated. However, on the other hand, it is suggested that increasing the premiums by insurance companies could harm insurance-purchasing rates by farmers.