The inter-monthly sea ice variation in the Southern oceans has been studied by the use of the area index data of sea ice from 1973 to 1986. The results show that: (1) the inter-monthly variation pattern of sea ice area in the latitude belt of 50°-79. 75°S is similar to that of 60°-69. 75°S; (2) in certain longitudes,this variation shows a tendency of Eastward (or west ward) propagation; (3) in general, the maximum and minimum of sea ice area appear in February and September respectively. But in certain longitudes, the months occurred extreme values can move up or delay.