Abstract : Experimental investigation to enhance the heat storage ability for the parabolic trough collector (PTC) is performed in this study. The performance of the PTC has been integrated with paraffin wax manufactured in Baghdad, Iraq. It has been evaluated experimentally based on the ANSI/ASHRAE 93-1986 standard. A special design for the heating water system is built with a continuous flow and a maximum temperature range of 65 oC. Water is used as the primary working fluid. The operation conditions include constant flow rate of 0.056 kg/s, direct solar radiation range from 120 w/m2 to 895 w/m2. The results show that with an incidence angle of 0, the highest efficiency for the collector is 0.82 %. The results also show that the paraffin wax has a crucial role to absorb the solar energy during the day and disperse the solar energy to the working fluid after sunset.