The lamp using Sodium vapor is used widely as a light source in experiments related to diffraction grating. The main point of sodium is that,it has high end emission wavelengths values. Also it is to be noted that without the help of sensitive equipment, the values of its wavelength cannot be measured. The purpose of this paper is to find out the wavelength of Sodium Doublet Emission (SDE) lines using diffraction grating. In this paper, it is proposed to find the values of SDE lines, F1 and F2, and also the mean wavelength as well as difference between the two SDE lines of sodium. In this approach, standardizing a spectrometer for evaluating the SDE lines has been proposed with the help of interference pattern created. With the aid of diffraction grating it is possible to obtain a well-defined and well resolved spectrum for the analysisofSDE lines. In this approach, the values for D1 and D2 are given by 588.9950 and 589.5924 nanometres respectively. In addition to the above, wavelength of SBE lines is evaluated and compared with theoretical value. The other parameters like angular separation, resolving and dispersive power of spectrum are also evaluated using this technique.