. In this manuscript, the second order differential operators with constant delay and transmission boundary conditions are studied. The asymptotic forms of the characteristic functions and eigenvalues of the operators are obtained. Therefore, an inverse spectral problem of recovering the operators using the spectra of two different Dirichlet-Dirichlet and Dirichlet-Neumann problems, is investigated. For this purpose, to prove the uniqueness of the potential, the integral equations of the potential function are formulated and then utilized. Indirectly, by calculating the coefficients of Fourier series, the potential function is reconstructed.
