The ethylene-regulated hypocotyl elongation of Arabidopsis thaliana's involves many transcription factors. The specific role of MYC transcription factors in ethylene signal transduction is not completely understood. The results here revealed that two MYCs, MYC2 and MYC3, act as negative regulators in ethylene-suppressed hypocotyl elongation. Etiolated seedlings of the lost-of-function mutant of MYC2 or MYC3 were longer than wild type seedlings. Single- or double-null mutants of MYC2 and MYC3 displayed an enhanced response to ACC(1-aminocyclopropane-1-carboxylate), the ethylene precursor, compared to wild type seedlings. MYC2 and MYC3 directly bind to the promoter zone of ERF1, suppressing its expression. Additionally, EIN3, a key component in ethylene signaling, interacts with MYC2 or MYC3 and suppresses their binding to ERF1’s promoter. MYC2 and MYC3 play crucial roles in the ethylene-regulated expression of functional genes. The results revealed these transcription factors’ novel role and functional mechanism in ethylene signal transduction.