  The asteroid (25143) Itokawa is a target object of the Japanese sample return
mission, HAYABUSA. We have observed Itokawa in optical wave- length (R-band)
with the 1.05-m Schmidt telescope at the Kiso Observatory, the 2.24-m telescope
of University of Hawaii, and the 1.05-m telescope at the Misato Observatory
since 2001. From the analysis of the data, we present the relationship between
brightness and the solar phase angle, 6.9 to 87.8 deg. We obtained the absolute
magnitude H_R(0) = 19.09+-0.37, and the slope parameter G_R = 0.25 +- 0.29. The
rotational period of Itokawa is 12.1324 +- 0.0001 hours.
