Abstract: To regulate the pore structure of poly（lactic acid） （PLA） nanofibers， the nanofibers with an average diameter of 1.37 μm were prepared through electrospinning using PLA masterbatch as a raw material and the chloroform （CF）/N， N-dimethylformamide solution as a solvent， and their structures were investigated. The results indicated that the average diameter of the resultant nanofibers increased with an increase in the CF content， polymer concentration， and ambient humidity. With improving the spinning voltage and the filling speed， the average diameter tended to decrease. Meanwhile， environmental humidity has a significant effect on the pore structure of the fiber surface. The distribution density of pores on the fiber surface increased with an increase in humidity， and the shape varied from round to oval. In addition， the specific surface area of the as-prepared porous fiber was increased by 10 times （24.0 m2/g） compared to that of the PLA nanofibers with a smooth surface （2.4 m2/g）.

Key words: poly（lactic acid）, electrostatic spinning, micro-nano fiber, porous structure