Abstract: Polypropylene (PP) fibers were electrospun by a self-made slit-surface melt differential electrospinning device, and effects of process parameters such as spinning voltage, spinning distance and spinning temperature on the interjet distance were investigated. The results indicated that the interjet distance decreased with an increase in spinning voltage but increased with a decrease in spinning distance. After the spinning distance was lower than 8 cm, the interjet distance was kept stable with a variation of spinning distance. The interjet distance also decreased with an increase in spinning temperature. However, the interjet distance was kept stable after the spinning temperature was higher than 230 ℃. The interjet distance achieved the minimum value of 3.3 mm at a spinning voltage of 60 kV, a spinning distance of 100 mm and a spinning temperature of 245 ℃.