If the solution concentration c and the spectral absorbance A is not obeyed Lambert-Beer’s Law, an individual solution sample should be prepared and acquired in order to obtain its infrared spectrum. The binary linear regression analysis and hybrid spectrum were applied to NaCl aqueous solution. The following conclusions have been reached: (1) The infrared spectra of NaCl aqueous solutions with concentrations of c₁, c₂ are $A_{c_1}$,$A_{c_2}$, respectively. Then the regression equation A_hc(c₁, c₂)=$\hat{a}A_{c_1}+\hat{b}A_{c_2}$ is set up, where the relationship among c₁, c₂ and c is c₁<c<c₂. Hybrid spectrum A_hc(c₁, c₂) can be very similar to real spectrum A_c if $\hat{a}$ and $\hat{b}$ values are selected properly. (2) The smaller difference between c₂ and c₁, the higher similarity between A_hc(c₁, c₂) and A_c is. (3) The regression equation A_hc(2%, 30%)=$\hat{a}$A_2%+$\hat{b}$A_30% can be applied to the concentration range 2%~30%. (4) The relationships between $\hat{a}$ and c, $\hat{b}$ and c are c=-3.592c+1.058 9 and $\hat{b}$=3.565c-0.055 15. If we select c, we can easily obtain $\hat{a}$ and $\hat{b}$ then $\hat{a}$ and $\hat{b}$ are substituted into regression equation A_hc(c₁, c₂)=$\hat{a}A_{c_1}+\hat{b}A_{c_2}$. All hybrid spectra are very similar to the real spectra and they can even replace the real spectra.