Abstract: Kapok is a kind of natural fiber with void content more than 85%,very suitable for thermal insulation material.However,because of its′ low tensile strength and compressional resiliency,the traditional kapok wadding is losing its market share.The newly developed kapok wadding by unique technique has overcome the above shortcomings.In order to gain further understanding of the comprehensive properties of the kapok wadding,a comparative study of static thermal resistance and convection heat transfer of kapok wadding and other fibers wadding is conducted,and it is found that in terms of warmth retention property,kapok is only second to the feather and obviously superior to 4-or 7-hollow polyester fiber wadding and spray-bonded nonwoven fabric.When compared with manufactured fibers wadding,kapok wadding has compact and tiny voids,making it have lower convection heat transfer and higher thermal transmittance resistance.