The features of the periodical variation in the tropical convective activity, its horizontal structure and the 30-50 day oscillation were analyzed with the 1979-1984 outgoing longwave radiation (OLR) data, and the anomaly of winter convection in the El Nino year (1982) was discussed in detail. Results show that the feature of the dual-element state of climate system could be reflected by the seasonal mean activity of convection. The convective disturbance is not marked by a dualelement state but it becomes relatively strengthened in the eastern Pacific during thd El Nino year, yet with a center of action of the disturbance west of the dateling. The 30-50 day oscillation of the convection travels eastward along the equator, crossing the dateline into the eastern Pacific in the El Nino year and trapped to the west in normal years in general.