Objective The current study aimed to clarify quant. electroencephalog.(EEG) characteristics of children with tic disorders(TD), discuss possible mechanisms of tic disorders, andexplore the application value of quant. EEG for the diagnosis and treatment of tic disorders. Methods EEG data of 104 children with tic disorders(TD group) treated at the Departemnt of Pediatric inBeijing Tiantan Hospital, Capital Medical University between Jan. 2019 and Dec. 2019 wereretrospectively analyzed. EEG data were screened for specific time periods without obvious artifacts. Therelative α, β, θ and δ bands energy, θ/β ratio, and spectral boundary of Fp1, Fp2, F3 and F4 wereextd. Forty-nine children matched by sex and age were randomly selected as the control group forstatistical anal. Results In comparison with the control group, children with tic disorders, Fp1, Fp2 showed higher relative θ band energy(Z = 2.354, P = 0.019; t =-2.351, P = 0.020) and higher θ/β ratio(Z =1.990, P = 0.047; Z = 2.206, P = 0.027), F3 showed higher relative δ band energy(t =-2.107, P = 0.037), F4 showed higher relative θ band energy(Z = 2.342, P = 0.019), higher relative δ band energy(Z = 2.510, P =0.012) and higher θ/β ratio(Z = 2.266, P = 0.023); Fp1, Fp2, F3 and F4 showed lower relative α bandenergy(Z =-3.005, P = 0.003; Z =-2.829, P = 0.005; Z =-2.905, P = 0.004; Z =-2.849, P = 0.004); F4 showed lower relative β band energy(Z =-2.022, P = 0.043). No significant difference was identified inspectral boundary(P > 0.05, for all). Conclusions sThe results suggested that the primary lesion of ticdisorders mainly involved the frontal cortex, and lead to brain excitation-inhibition imbalance. QuantitativeEEG can provide objective evidences for the diagnosis and treatment response assessment of patients withtic disorders.