Abstract: This paper develops a method for decreasing the TTFF and fast fixes position in the Aided Global Position System (AGPS), which also analyzes the influence of local time accuracy and pseudo range deviation. The simulation results show that the new method can correctly predict pseudo range and give out the accurate users' position in 1 second of TTFF, when the RTC's average error could be around 27 seconds and the predicting satellite position's average error could be about 87 kilometers; the same situation for 4 seconds of TTFF, when the RTC's average error could be around 1 minute and the predicting satellite position's average error could be about 200 kilometers; this can be applicable in many circunstanses.