A theoretical study of the thermal behavior of salt-gradient solar pond located in Cairo (latitude angle 3005'N and longitude angle 3117'E) is presented in this work. The present model is chosen for thermal analysis of six salt-gradient layers of the solar pond. One-dimensional time-dependent solar energy absorbed in six layers of the solar pond of the present solar pond is applied using Fresnel's equations. The vertical temperature variation through six layers during the days of the month year round is presented. The daily temperature fluctuations are smallest for larger depths and about 12C for the 137.5 cm. The theoretical form of the absorption of solar radiation by salt gradient of water layers is presented. The solar radiation transmission through the layers of the present pond is illustrated. The amount of energy absorbed by the layers of the salt gradient is predicted during the days of the month around the year. The mean amount of absorption energy in the layer (1) is 55,196.1 cal/cm2/day at 12.5 day hour.