Interlacer is the key part of interlacing technology that is adopted to improve the cohesion between loose multifilaments. Aimed at finding the interlacers with better performance, the present research designed five interlacers that can be classified into round type and cornered type. These five interlacers are different in cross-sectional shapes of yarn channel but are the same in the cross-sectional area. The evaluation of the performance of the interlacer includes the number and the strength of the tangles of the interlaced yarn it produces. Experiments are carried out at various supplied air pressures, yarn speeds and feed ratios. It was found that the interlacer with round cross-sectional shape of yarn channel is capable of producing an interlaced yarn with a large number of tangles and the cornered cross-sectional shape is effective in improving the strength of tangles. Among these five interlacers, the interlacer with an elliptical or an inverse-triangular shape has the best processing performance