This paper extend Jiang and Tian( 2005) model to the setting for put options，and obtain the expres-sions of the model-free implied volatility of call options and put option． And we further transform the theoreti-cal expressions to those which meet practical application needs． According to no-arbitrage principle，we construct calls and puts with different strike prices using the deposit and lending interest rates with various maturi-ties and then we acquire a series of calls and puts through cubic curve fitting method． Finally we work out the implied volatilities of five-year deposit and lending interest rates． Our results show that there exists a upward pressure in the interest rates of deposit and lending of China’s banks．