To improve capillary performance, twenty kinds of porous wicks were sintered with copper powder as material and sodium carbonate as pore former. Capillary rise height was measured and watched by infrared imaging method with an infrared thermal imager and a high speed camera, using water as working fluid. Comprehensive effects of particle diameters (d=556 nm-73.8 μm) and pore former proportions (β=0-0.4) were investigated. The results show both particle diameters and pore former proportions have effects on capillary rise height. Micron particles have higher capillary rise height than nano-particles. Capillary performance of wicks can be enhanced by adding a certain amount of sodium carbonate to change internal structures of wicks during the sintering process. Different particle diameters correspond to an optimum pore former proportion which decreases with increasing particle diameters. There is a best matching relationship between powder particle diameters and pore former proportions. For wicks with d=38.8 μm and β=0.2 the maximum capillary rise height can reach 536 mm.