Prediction and observations of Leonid meteor shower in China

Recent years, observations by both visible and radio have been performed under the organizing of Chinese Leonid Watch. We have observed some interesting phenomena, like the filamentary structure of the shower, the variations of the size distribution of meteoroids and the mass density. In addition, we made progress in their data processing. We observed the expected main shower in 1998 with radio. An abnormal peak in the ionosphere characteristic value was also detected about 18 hours after the main shower. From the fundamentals of celestial mechanics, we find the differences between the longitude of the ascending node of meteoroids and that of their parent comet depends on the ejection position as well as the ejection velocity. We successfully predicted the Leonids in 1999 and 2000.