Abstract: The pipe bend will significantly change the propagation characteristics of guided wave, and make the interpretation of detected signal difficult. So, the effect of pipe bend on the propagation characteristics of guided wave should be the key to the detection of complicated pipeworks. First of all, the features of dispersion curves for bended pipes, which are derived with the semi-analytical finite element method, are summarized. Secondly, based on the dispersion curves for bended pipes, experiments of bended pipe detection have been conducted to show the mode conversion of L(0, 1) mode guided wave due to pipe bends. It is found that, except for the L(0, 1) to F(1, 1) mode conversion, the L(0, 1) reflections of bends are also observed in some cases, which has been proven to be the negative L(0, 1) mode guided wave mode converted from the incident L(0, 1), and the negative L(0, 1) mode guided wave becomes more obvious with the decreasing of excitation frequency and bend radius. The study results will deep the understanding for propagation characteristics of guided wave in bended pipe, and generalize the application of guided wave detection in complicated pipeworks.