Abstract: Electromagnetic waves may be trapped when they propagate in atmospheric ducts which often occur in marine environments,as a result,the propagation characteristics are quite different from that in normal atmosphere conditions.The aim of this article is to study the anomalous propagation characteristics caused by atmospheric ducts using the numerical simulation and experimental validation.Brief description of parabolic approximation equation model and its marching type Fourier algorithm is introduction,which is used to numerically simulate electromagnetic waves propagation in different kinds of atmospheric ducts,form the results,we get some conclusions associated with the trapped effect of ducts environments,the experimental data extracted from HangZhou Gulf Experiment on May 6 of 1999 is analyzed to validate the anomalous propagation characteristics.