EVA Air also has purchase rights for four more airplanes.
"The 777-300ER is the flagship of our long-haul fleet and will play an important role in growing our global operations," Chang Kuo-wei, president of EVA Air, said in a press statement.
EVA Air and GE Capital Aviation Services also announced on Tuesday that the carrier will lease four additional 777 from GECAS. The leasing company already has those airplanes on order with Boeing for delivery in 2014.
The Taiwan-based carrier already operates 15 777-300ER aircraft. EVA Air is growing its airplane fleet to increase frequency to mainland China and new destinations in North Asia.
"EVA Air was a launch customer for the 777-300ER in 2000 and today the airline is among the leading global airlines operating out of Asia," Ray Conner, senior vice president of Sales for Boeing Commercial Airplanes, said in a statement.