There are a lot of complex environmental vibrations induced by mechanical equipment, vehicles, wind, ocean waves, etc. Meanwhile, these environmental vibrations usually own broadband and time-varying characteristics, which bring difficulty to efficiently harvest energy from such vibrations. The nonlinear vibration energy harvester is one of most effective energy harvesters to convert vibration energy into usable electric energy. Based on recent research progress of his group, this presentation will discuss the design, nonlinear dynamic analysis and experimental tests of nonlinear vibration energy harvesters subjected to various excitations, such as broadband base excitations, wide ranges of rotational speeds and wind speeds.