Abstract: Aim\ To study the absorpt characteristic of human tissue for laser irradiationMethods Based on the Beer law to study the laser absorption characteristics of water, proteins and pigments to get those of skin, aortic wall and cornea for laser irradiation of variant wavelength WTHZResults WTBZIt is shown that absorption in the UV and visible range of the spectrum is primarily dependent on pigments while water molecules mainly absorb irradiation in the IR region of the spectrum Conclusion The set of Er lasers whose wavelength falls in the range of absorbtion peak of water is very importent