The ARPN Journal of Engineering and Applied Sciences Vol.13 Issue 24 has published the scientific research entitled (Calculation Of Absorption And Emission Of Thermal Radiation By Clouds Cover) by the lecturers at the college of science Dr. Usama Tariq and the researcher Zainab Majeed. The research studied long-wave radiation absorbed and emitted by clouds within certain wavelengths during hourly mean 00-12 times and a cycle in temperature variation. So, classified the clouds according to the cloud thickness and pressure levels as well as we studied the relationship between the cloud water content and the absorbance and relationship between the saturated vapor density and the emissivity. The results showed that absorption and emission depend on the cloud thickness, the cloud water content, saturated vapor density, cloud location and wavelengths, where the higher clouds absorption lead to clouds emission higher during hourly mean 00-12 time.