"Fully Dynamic 2-Edge Connectivity Algorithm in Polylogarithmic Time per Operation" Monika Rauch Henzinger and Valerie King Note #1997-004. June 12, 1997. 14 pages. This paper presents the first dynamic algorithm that maintains 2-edge connectivity in polylogarithmic time per operation. The algorithm is a Las-Vegas type randomized algorithm. For a sequence of Omega(m_0) operations, where m_0 is the number of edges in the initial graph, the expected time for p insertions or deletions of edges is O(p log^5n) and the worst-case time for a query is O(log n). If only deletions are allowed then the cost for p updates is O(p log^4n) expected time.