This study compared the scale of infant pain during vaccinated injection using conductance skin electric (Skin Conductance), the Wong-Baker Faces Scale (WBFS) instrument, and Face Leg Activity Cry and Consolability (FLACC) instruments. It was observational cohort study with pre-experimental design using vaccinated injection as pain stimuli. This study investigated 121 infants (59 boys, 62 girls), age/PNA 4.37 ± 2.97 months, and current body weight 6522 ± 1378.65 grams). Most infants had adequate birth weight 71 (89.9%) about 2985.74 ± 405.83 kg and mature infants as 67 (84.4%), about 38,52 ± 2,09 weeks. Pain measurement of all three instruments was do simultaneously using a developed Skin Conductance (SC) apparatus and video recording (to assess behaviour and face). WBFS, FLACC and SC have the same significance in measuring infants' pain scale during vaccination injection. Statistical analysis showed a significant difference in the three pain measurement instruments between before and during injection with a p value of <0.001. So that SC can be recommended for pain measurement.