The influence of the splitter plates on the high-current arc roots formation in low voltage circuit breaker is investigated. One arc quenching chamber model is designed, where the shape of the splitter plates can be changed. The capacitor bank circuit is used to provide the test power supply, and the effective value of the prospective short circuit current is fixed to 10kA. High speed CCD camera is adopted to record the arc images during the arcing duration. Arc current and voltage are also measured to analyze the arc characteristics. In addition, a simplified 1-D thermal-electric model is developed to investigate the influence of the splitter plates on the distribution of the current density of the arc plasma with the assumption of local thermal equilibrium (LTE). It shows that the distance between the arc initial ignition location and the splitter plates is crucial to the arc root formation.