Using the symmetry-adapted-cluster-configuration-interaction (SAC-CI) method provided by the Gaussian 03 program package, the potential energy curve for 7Li2(23Πu) has been calculated with the basis set 6-311++G(d,p) over the internuclear separation range from 0.13 to 2.0 nm. And the ab initio calculated points have been subjected to a least squares fitting to Murrell-Sorbie function. Employing the Rydberg-Klein-Rees method, the harmonic frequency is derived from the analytic potential energy function and then other spectroscopic data are further computed. These spectroscopic data are Te=3.6701eV, De=1.0764eV, Re=0.3000nm, ωe=285.69cm-1, ωeχe=1.8351cm-1, αe=0.00942cm-1 and Be=0.5340cm-1, respectively. In particular, the present Te, De, Re and ωe　values are in excellent agreement with other theoretical results. With the analytic potential energy function obtained on the SAC-CI/6-311++G(d,p) level, a total number of 67 vibrational states for the 23Πu state is found when J=0 by solving the radial Schrdinger equation of nuclear motion. The complete vibrational levels, classical turning points and inertial rotation constants for these vibrational states are also reported. The reasonable dissociation limit for the 23Πu state is deduced using the present results calculated.