Abstract: According to the acoustic emission (AE) signals detected in resistance spot welding (RSW) on galvanized steel sheet, the main inducing factors of welding spatter were analyzed by orthogonal experimental design (OED) and the analysis of variance (ANOVA). The results showed that the equivalent released energy by welding spatter can be assessed by two characteristic parameters: positive peak value and AE count. The most important factor inducing welding spatter is welding current, the second factor is pressure. The importance of welding duration and interaction of welding current and electrode pressure is close. The welding current and welding duration have a positive effect on the equivalent weight of spatter. While the electrode pressure has a negative effect on the equivalent weight of welding spatter.