Abstract: In order to study the influence of idling number on fabric properties, six kinds of Milano rib as example was knitted with different idling number by the same yarn which were tested for the properties of weight, thickness, heat retention and air permeability，and correlation analysis was carried out. The experimental results revealed idling number was highly negative correlation with the weight and air permeability. The weight and air permeability decreased with increasing of idling number. The idling number had not apparent linear correlation with thickness and heat retention which changed with first increasing and then decreasing as the increasing of idling number.

Key words: air layer stitch, idling number, property, correlation analysis, knitted fabric