The value of thermal insulating material is clear and obvious with the climate change and energy consumption．As a developing material，nanofiber applications for thermal properties are being actively investigated．Previous studies have shown that thermal conductivity between fibers and quantitative evaluation of radiation from the fiber surface，are effective for predicting the thermal conductivity of polymeric nanofiber nonwoven fabric which mass production by a melt-blowing method．However，the thermal transfer mechanism of nano scale diameter fibers is not well known．This study focused on the estimate the efficiency of thermal conductivity with two types of models．Also，the computational fluid dynamics flow-analyzing software was used to simulate the adiabatic property of the trial-produced nano-fabric． Consequently，the influence of fiber diameter and fabric thickness was verified，it is also be found that the proposed fiber diameter distribution model was closer to the experimental value．As a result，it can be used for estimation and evaluation the thermal conductivity characteristics of nano scale nonwoven fabric．
