The autocorrelation function is investigated in the formalism of entangled trajectory molecular dynamics. We investigate the contribution of individual trajectory of the entangled trajectory ensemble to the autocorrelation function, and show the vivid physical picture of the autocorrelation via individual entangled trajectory. Also, it is shown that the 'autocorrelation' of trapped entangled trajectory is bigger than that of escaped entangled trajectory. (C) 2013 Elsevier B. V. All rights reserved.