2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/198541I review recent developments in theoretical understandings of J/psi productions in various processes at Tevatron, B decay and J/psi photoproduction including the color-octet mechanism.Talk given in the KPS-JKPS Winter School held at Seoul, Korea during Feb. 21-28, 1996. To appear in the proceeding. Minor changesHigh Energy Physics - Phenomenologytext