Niobium diselenide (NbSe2) possess a high electrical conductivity and low thermal conductivity, making it a candidate for thermoelectric devices. While the electronic properties of (NbSe2) has been relatively explored, the lateral thermal conductivity for (NbSe2) has remained unknown. In this report, we present the lateral thermal conductivity of (NbSe2) determined by nondestructive opto-thermo method utilizing micro-Raman spectroscopy. The thermal conductivity k=15(+4/-4) W/mK was obtained at room temperature and we further verified by hall measurements that (NbSe2) conducts heat mostly through electrons. The results shed lights on the potential of Niobium diselenide as a thermoelectric device.