Heat generation and dissipation of the needle in sewing were investigated in order to improve the trouble due to the frictional heat. The cooling effect by the addition of lubricant and compressed air was also studied. Correlation coefficient between the needle temperature and penetration energy was 0.91, which represent very high correlation. Therefore, it was confirmed that mechanical energy of the friction between the needle and fabrics contributed to the rise of needle temperature. Heat transfer coefficient of the needle increase proportionally with increase of sewing speed and the heat transfer of unit length of the needle also increased. Addition of lubricant to the sewing thread was effective to pvevent heat generation of the needle and breakage of the sewing thread. The cooling method of the compressed air was very effective one, and heat transfer of unit length increased by square root of air velocity.