Abstract: Reference datum of global crustal horizontal motion was studied.ITRF2005VEL was obtained based on Euler law and ITRF2005 velocity field,the total angular momentum of the tectonic plates was also calculated and discussed.The absolute plate motion model NNR-ITFR2005 was established based on NNR(no-net-rotation) reference frame through constraining the velocities of ITRF2005 by using the condition of discrete Tisserand,and was compared and analyzed from geological model NNR-NUVEL1A and the other ITRF series NNR models.The results show that there is a better consistency of NNR-ITRF2005 and NNR-NUVEL1A model in whole.While,at the same time,there inevitably exist some differences between NNR-ITRF2005 and NNR-NUVEL1A which are related to the factors of lacking of observation stations,uneven station distributions,short observation times,not enough constraints to plates,and some problems of themselves and so on.At last,the net rotation of the lithosphere was also discussed.