We have studied Sn plasma which is produced by different laser wavelengths and different pulse durations. Laser produced Sn plasma is currently considered as a candidate for an EUV radiation source. Studied Sn as an efficient target to produce 13.5 nm EUV radiation, has many applications such as lithography application. As well as laser produce Sn plasma is consider as a lasing media at 11.9 nm, as it is relatively produced high gain. The research consists of three topics: First, the electron temperature and density were estimated from the analysis of spectral data. The electron temperature measurements have been performed by line ratio method using different wavelength transition of many Sn spectrums, while the electron density measurements were made using the Stark broadening method using singly ionized Sn lines for the wavelength 645.4 nm. Second, we have studied refractive index for Sn plasma, using a formula which shows the effect of the bound electrons on the refractive index using interferometry experiments. Final, we studied the conversion efficiency for Sn plasma using two theories, A. study the conversion efficiency through the delay time and indicate the density-dependen