The purpose of this paper is to investigate heat dissipation performance of porous copper with long cylindrical pores fabricated by a unidirectional solidification method.Three samples with porosity of 29.87%,34.47%and 50.98%were chosen and cut into size of 60 mm(length)26 mm(width)2 mm(thickness)along the vertical direction of pore axis.Their heat dissipation performance was evaluated by a nonsteady method in air and compared to those of not only bulk copper but also bored coppers with porosity of 30.61%and32.20%.It is found that the porous copper dissipated heat faster by a forced air convection than that by natural convection from 80 C to room temperature and both porosity and pore size play an important role in the performance for the porous copper.Furthermore,the heat dissipation rate is higher when the forced air was circulated along the specimens than that perpendicular to the specimens for the porous copper.It is revealed that porous copper with bigger porosity and a proper pore size possesses a higher heat dissipation rate.It is concluded that the porous copper with elongated cylindrical pores has larger heat dissipation performance than both the bulk copper and the bored copper,which is attributed to its higher specific surface area.Application of the porous copper for heat dissipation is promising. The purpose of this paper is to investigate the heat dissipation performance of porous copper with long cylindrical pores fabricated by a unidirectional solidification method. Three samples with porosity of 29.87%, 34.47% and 50.98% were chosen and cut into size of 60 mm (length) 26 mm (width) 2 mm (thickness) along the vertical direction of pore axis. Their heat dissipation performance was evaluated by a nonsteady method in air and compared to those not only only copper but also bored coppers with porosity of 30.61% and 32. 20% .It is found that the porous copper dissipated heat faster by a forced air convection than that by natural convection from 80 C to room temperature and both porosity and pore size play an important role in the performance for the porous copper. heat dissipation rate is higher when the forced air was circulated along the specimens than that perpendicular to the specimens for the porous copper. It is revealed that porous copper with larger porosity and a proper por e size possesses a higher heat dissipation rate. It is concluded that the porous copper with elongated cylindrical pores has larger heat dissipation than both the bulk copper and the bored copper, which is attributed to its higher specific surface area. Application of the porous copper for heat dissipation is promising.