Negative evidence could increase the strength of specific arguments in semantic category-based inductive reasoning, but whether the effect still exists for general arguments, more importantly, the mechanism of the cognitive processing of general arguments, remains unclear. In the current study, event-related potentials (ERPs) were used to investigate this effect by controlling the category type (related vs. unrelated) and argument type (positive vs. negative) in general arguments. The behavioral results demonstrated that under the unrelated-category conditions, negative arguments had a greater argument strength and were associated with a shorter reaction time than positive arguments. The ERP results indicated that in the premise 2 presentation phase (a) unrelated categories elicited larger P300 and N400 amplitude than did related categories, reflecting the categorization process, and (b) positive properties elicited larger P600 amplitudes than did negative properties, demonstrating the process of property judgment. In the conclusion phase (c) negative arguments elicited larger P2 and N2 amplitudes than did positive arguments, which embodied cognitive control and conflict detection, and (d) negative arguments also elicited a SN than did positive arguments under the related-category condition, which illustrated the property inference. This study provides robust evidence that negative evidence can increase the argument strength in general arguments, and that the temporal course of negative evidence influences the inductive strength.