Abstract
The IHY Japanese National Steering Committee (STPP subcommittee of the Science Council of Japan) has been promoting and supporting (1) two satellite missions, (2) five ground-based networks, (3) public outreach, (4) international and domestic workshops, and (5) the nomination of IGY Gold Club members. In the present paper we introduce these IHY activities, briefly summarize them, and suggest several post-IHY activities.