1, coupon rate and real interest rate are two important interest rates of bonds: coupon rate is the interest rate marked on bonds for quotation, while real interest rate refers to the real interest rate that investors get interest returns after excluding inflation rate, which is used for calculating returns.

2. coupon rate is not necessarily equal to the real interest rate: if bonds are issued at face value, the real interest rate is equal to coupon rate; If bonds are issued at a premium (sold at a high price), the real interest rate is lower than that of coupon rate; If bonds are sold cheaply in at discount, the real interest rate is higher than that in coupon rate.