Abstract: Based on over 10-year timing data for 12 millisecond pulsars from the Parks telescope at Australia Telescope National Facility, TOAs (time of arrival) for these millisecond pulsars and their errors were solved using the cross-correlation technique. The corresponding timing residuals in Barycentric Coordinate Time were analyzed and then the Ensemble Pulsar Timescale model was constructed using Fourier series in order to realize Terrestrial Time. The stability of the timescale was evaluated with sz method. The results show that the stability of the ensemble Pulsar Timescale reached 10-15 over 10 years, presenting a linear increasing trend with an a upward tendency over time. The stability could rise with a longer observation time. White noise is the primary noise source and its impact on stability of the timescale decreased over time. Ensemble Pulsar Timescale could be considered as a realization of Terrestrial Time since the stability of the timescale is comparable to that of BIPM (2013).