The Japanese QZSS (Quasi-Zenith Satellite System) orbit covers the Asia Oceania region. Australian GNSS users will benefit from the QZSS navigation service significantly once the system service becomes mature. The benefit is not only from the additional navigation satellites of the new system, but also the potential of accessing to the high accuracy orbit, clock, and regional ionospheric model for all GNSS satellites broadcast by the JAXA-LEX signal. In this research, the usability and feasibility of the JAXA-LEX navigation service in Australia were assessed; the GPS satellite orbits, clocks and ionospheric model broadcast from the JAXA-LEX signal were compared with the IGS final products. To assess the quality of point positioning estimates, data collected at several Australian CORS stations were processed using Precise Point Positioning (PPP). The results show that the Australia available GPS orbit and clock broadcast by the JAXA-LEX signal can mostly achieve accuracies of better than 0.5 metres and 1 nanosecond respectively, although some limited number of satellites may not get improvement. The ionospheric correction parametres provided by the JAXA-LEX signal are much worse than the IGS counterparts and so they are not suitable for Australian GNSS navigation users. The accuracy of the positioning results from the dual-frequency (ionosphere-free) PPP processing and the current QZSS LEX orbit and clock have about 0.3 metres accuracies in horizontal, and the vertical accuracy is about 0.6 metres