传统的存贷利差就是贷款利率和存款利率之间的差额。本文利用金融工程学的基本原理提出了银行资产负债业务中隐含着期权的全新观点，因此银行的真实利差并不等于存贷款利率差额，还要考虑银行所承担的期权成本以及违约风险。文章对银行资产负债业务中隐含期权进行了分解，分析其隐含期权的特征以及各个因素对期权执行可能性的影响。接着通过两种方法――无套利分析和数值计算法对隐含期权进行了定价，并进行了期权价格对各个因素的敏感性分析，得出了许多具有重要创新意义的结论。分解之后可以发现银行的真实利差明显偏低，贷款动力明显不足。 The traditional saving-loan interest rate spread is just the spread between the loan rate and saving rate. By the methods of financial engineering, this paper points out that the basic asset and liability of bank includes some options which are sent to the customers for free by the bank. Then the real interest rate spread is not just the saving-loan rate spread, the options cost should be also considered. This paper decomposes the implied options in the asset and liability operations of bank, analyzes their characters and the impact of different factors on the execution possibility of option. Two methods, no arbitrage analysis and numerical methods are used to price the implied options and the sensitivity test of option price on different factors is given out. By these, many constructive conclusions are drawn out.