The increase of cargo volumes and demand of vessels have led port authorities to improve infrastructure, enlarge area, and construct another port to become a hub port in Asia. The paper examines efficiency of 37 Asian container ports by applying a Data Envelopment Analysis. We find that large ports such as Singapore, Shanghai, Hong Kong, Shenzhen, Kaohsiung etc. are competitive in technical aspect. We also find that 23 out of 37 ports have a structure of increasing return to scale, that is, they increase revenue proportionate to the scale. However, the finding shows that a mega size port is certainly a positive factor to improve efficiency, but does not necessarily augment port efficiency.