The paper discusses two treaties that are being negotiated: Multilateral Treaty, which bans all nuclear weapon tests and establishes a moratorium on PNEs (Peaceful Nuclear Explosions) for the life of the treaty, and a separate verification agreement, which provides for much more extensive verification measures that does the Multilateral Treaty and to which only the US, UK, and USSR will adhere. On the latter treaty, agreement has been reached that there will be improved seismic stations (NSS) in each country. Discussed are the outstanding general points of agreement or disagreement on NSS; technical characteristics of NSS; and a joint cooperative program for NSS.