Abstract: Eight kinds of light-weight polyester/cotton/hemp blended fabric with different blending ratio and with yarns spun by different spinning methods were selected for investigating their thermal comfort. By using US-made humidity chamber and Sweating Guarded Hotplate, the thermal conductive property of the fabric was simulated under 11 designed temperature and humidity conditions. The objective of this study is to find the influence of blending ratio and spinning methods on the thermal comfort of multi-fiber blended fabric and the thermal comfort conditions of polyester/cotton/hemp blended fabric. The results indicate that among four major factors including temperature, humidity, blending ratio and spinning method, blending ratio has little effect on fabric thermal resistance, while spinning method is the most influential factor; whatever the condition is, the fabric made from sirofil-spun yarn is better than that made from siro-spun yarn in term of thermal transmission and the former is cooler than the latter; under the condition of temperature above 20 oC and relative humidity below 60%, the thermal resistance of the fabric is low and stable, which

Key words: hemp; polyester/cotton/hemp blended fabric; thermal resistance; thermal comfort contribute to the fabric comfort.