High-resolution spectra of the B-1 Pi-->X(1) Sigma(+) transition of (NaRb)-Na-23-Rb-85 molecule are measured by the technique of the Doppler-free optical-optical double resonance polarization spectroscopy (OODRPS). The molecular constants of the X(1) Sigma(+)(v"=5-30) levels are determined, and the potential energy curve is constructed up to v"=30 by the RKR method. The time-resolved fluorescence intensity following the excitation to the B-1 Pi(v’=5,J’=around 20) level is measured, and the lifetime of the B-1 Pi(v’=5) level in collisionless limit is determined to be 17.8 ns. The absolute value of the electric dipole moment of the B-1 Pi-X(1) Sigma(+) transition is determined to be 7.0 D in the region of 3.73 Angstrom

Keywords:HYPERFINE