In this work, we study a diagnostic of a copper-plasma in air using a fundamental wavelength of a Nd: YAG laser system. The optical emission spectra of copper-plasma that have been detected using a spectrum analyzer (Thorlabs GmbH) have been used to extract the excited plasma temperature via the Saha-Boltzmann method, and measure the electron number density by McWhirter criterion. Measured values of Ne and (Te) is in the range of (14890.827 K°) and (Ne) is (2.7*1015 cm-3) at the fundamental wavelength.