Abstract: Abstract：For a traditional condenser with tubeside vapor condensation vapor is completely condensed in one flow route without phase separation，and condensate accumulates to form thick film and complicated two phase flow which greatly decrease heat transfer coefficient and system stability and increases pressure drop. The way to enhance the performance of heat transfer is adding fins and/or inserts. Employed a very fine structure design，a kind of new high performance condenser was invented. This kind condenser would automatically separate liquid from vapor and make condensation always occur in short tubes or the entrance regions with droplet and unsteady thin film condensation mode in the whole condenser，which results in very high average heat transfer coefficient. An introduction is presented to describe the basic principle of a novel heat exchanger technology，particularly the understanding from the fundamental experimental investigations and industrial tests.