Optical emission spectra of the plasma generated by a 532 nrn Nd:YAG laser irradiationonto a standard aluminum alloy (E414d) was recorded and analyzed. The electron temperaturewas determined using the Boltzmann plot method with three aluminum spectral lines at236.71 nm, 257.509 nm and 308.215 nm, whereas the electron density was inferred by measuringthe Stark broadening line profile of Al(Ⅱ) 281.619 nm. The experimental results confirmed thatthe local thermodynamic equilibrium was valid and the plasma was optically thin. The spectralline intensity increased initially with the increase in laser irradiance and saturated at higher irradiancelevels. Results showed that the energy losses due to the reflection of laser beam fromthe plasma itself were insignificant. The absorption in the plasma through inverse bremsstrahlungand two-photon ionization were studied. At the same time, the variation of transition probabilityratio of Al(Ⅰ) 309.28 nm to Al(Ⅰ) 308.21 nm with laser power density was also studied. Optical emission spectra of the plasma generated by a 532 nm Nd: YAG laser irradiationonto a standard aluminum alloy (E414d) were recorded and analyzed. The electron temperature was determined using the Boltzmann plot method with three aluminum spectral lines at 236.71 nm, 257.509 nm and 308.215 nm, while the electron density was inferred by measuring the Stark broadening line profile of Al (II) 281.619 nm. The experimental results that the local thermodynamic equilibrium was valid and the plasma was optically thin. The spectralline intensity increased initially with the increase in laser Results showed that the energy losses due to the reflection of laser beam from the plasma itself were insignificant. The absorption in the plasma through inverse bremsstrahlungand two-photon ionization were studied. At the same time, the variation of transition probabilityratio of Al (Ⅰ) 309.28 nm to Al (Ⅰ) 308.21 nm with laser power density was also studied