Alpha(α)-synuclein is closely related to the pathogenesis of Parkinson's disease (PD).The NACore, a fragment of α-synuclein, is considered to be the key region of α-synuclein that causes PD. The aggregation dynamics of NACores are studied via coarse-grained molecular dynamics simulations. We find that NACores can selfassemble into a large cluster at high concentrations. The aggregation dynamics can be divided into three stages. The growth kinetics for the first and second stages follows the power law, S max $ t γ , with the second stage faster than the first one. The characteristic lifetime for the high concentration is 40 times larger than that for the low concentration, implying the low fluidity. Understanding the aggregation dynamics of NACores is helpful to develop drugs for therapeutic prevention and intervention.