Environmental and energy issues demand the construction equipment industry to develop more efficient and energy-saving machines as they have done to the automotive industry in the past two decades. Construction equipments such as excavators, loaders, and forklift trucks, have unique power train mechanisms, thus raise unique technical issues with respect to efficiency improvement or energy savings. Traditionally hydraulic systems, which have unparalleled power density and ruggedness, have been the core parts of the construction equipments' power train. Due to heavy work load and long daily operation hours compared to automobiles, the economic impact of energy efficient equipment on customers' maintenance budget must be greater than that of automotives. Hence, there are challenges and opportunities in this industry for energy saving technologies like hybrid power trains. Although not popular yet, hybrid excavators made their debut in the market, and commercialization of hybrid loaders and forklift trucks will soon become a reality. Recent advances in power electronics and electric machines have played a crucial role in hybridizations of construction equipments.