Sand compaction pile method is a major method for countermeasures against sand liquefaction. This method is widely used by its economical efficiency and high certainty, but it has some weak points. Increase of N-value near the surface is not enough compared with N-value at deep points. Friction rod method is an auxiliary method of sand compaction pile. It can increase N-value near the surface by inserting iron rods. The effectiveness of friction rods was checked by the centrifuge model tests and field tests.