The spectrum of ZnIn shows bands which can be analyzed into four systems. Two narrow systems at $\ensuremath{\lambda}4102$ and $\ensuremath{\lambda}4511$ appeared continuous. Systems at $\ensuremath{\lambda}5308$ ($B\ensuremath{-}A$) and $\ensuremath{\lambda}5625$ ($D\ensuremath{-}C$) were photographed with a dispersion of 5 \AA{}/mm. A possible vibrational analysis has been made for them. These systems exhibit an isotope effect which shows ZnIn as the emitter. Probable electronic states are $^{2}\ensuremath{\Pi}\ensuremath{-}^{2}\ensuremath{\Sigma}$ for $\ensuremath{\lambda}5308$ and $^{2}\ensuremath{\Sigma}\ensuremath{-}^{2}\ensuremath{\Sigma}$ for $\ensuremath{\lambda}5625$. Constants obtained are as follows: for $B^{2}\ensuremath{\Pi}_{\frac{1}{2}}\ensuremath{-}A^{2}\ensuremath{\Sigma}$ subsystem, ${\ensuremath{\nu}}_{e}=18810.8$, ${{\ensuremath{\omega}}_{e}}^{\ensuremath{'}}=201.2$, ${{\ensuremath{\omega}}_{e}}^{\ensuremath{'}}{{x}_{e}}^{\ensuremath{'}}=0.6$, ${{\ensuremath{\omega}}_{e}}^{\ensuremath{'}\ensuremath{'}}=146.7$, ${{\ensuremath{\omega}}_{e}}^{\ensuremath{'}\ensuremath{'}}{{x}_{e}}^{\ensuremath{'}\ensuremath{'}}=0.7$; for $B^{2}\ensuremath{\Pi}_{\frac{3}{2}}\ensuremath{-}A^{2}\ensuremath{\Sigma}$ subsystem, ${\ensuremath{\nu}}_{e}=18831.2$, ${{\ensuremath{\omega}}_{e}}^{\ensuremath{'}}=193.9$, ${{\ensuremath{\omega}}_{e}}^{\ensuremath{'}}{{x}_{e}}^{\ensuremath{'}}=0.6$ and for $D\ensuremath{-}C$ system, ${\ensuremath{\nu}}_{e}=17732.0$, ${{\ensuremath{\omega}}_{e}}^{\ensuremath{'}}=107.0$, ${{\ensuremath{\omega}}_{e}}^{\ensuremath{'}}{{x}_{e}}^{\ensuremath{'}}=1.0$, ${{\ensuremath{\omega}}_{e}}^{\ensuremath{'}\ensuremath{'}}=56.1$, and ${{\ensuremath{\omega}}_{e}}^{\ensuremath{'}\ensuremath{'}}{{x}_{e}}^{\ensuremath{'}\ensuremath{'}}=0.1$.