Manganese doped zinc oxide was ablated on (100) silicon using the fundamental harmonics of Nd:YAG laser at various oxygen ambient gas pressures and temperature substrate was kept at room temperature during the deposition. In all experiments we used ZnMnO target. Optical emission spectroscopy (OES) is used to survey the plasma composition during deposition. The intensities of the ZnI and ZnII emission lines are correlated to the oxygen gas pressure and composition and morphology of the films deposited. Strong emission lines of ZnI, Zn II and neutral oxygen are observed. Oxygen and Mn emission lines in its atomic or ionic states have not been detected in this investigation, which is thought ZnMnO as being exclusively produced on the substrate surface and not generated into the plasma, which is in agreement with previous studies of ZnO plasma plume. Atomic Force Microscopy (AFM) is used to study the influence of oxygen gas pressure on the ZnMnO film morphology. An X-ray diffraction was tried to verify a crystal structure of the sample. We have demonstrated that gas pressure is an important parameter for the quality and performances of ZnMnO structures obtained by pulsed laser deposition.