The Determination of Rotation Parameters of the Hipparcos Input Catalogue to the IERS Extragalactic Celestial Reference Frame

The rotational parameters of the Hipparcos Input Catalogue(HIC) to the International Earth Rotation Service(IERS), Celestial Reference Frame(ICRF),which is based on the Very Long Baseline Interferometry(VLBI), are determined by the comparison of Earth Orientation Parameters(EOP) and the correspo ding Terrest rial Reference Frame(TRF).At the epoch J2000.0, the rotation of HIC to ICRF is 8.4±1.1mas, 46.7±1.1mas, 45.5±1.5mas, and the rate of this rotation is -0.14±0.05mas/a, 3.22± 0.05mas/a, 5.70±0.07mas/a. In considera tion of the fact that HIC is identical with FK5, the results of this paper are in consistence with the systematic difference of FK5 to ICRF.