Cone penetration test (CPT)has dual functions of site investigation and assessment,and is widely used in soil improvement.Taking the ground improvement of a LNGI project in the Middle East as an example,CPT technology is widely applied in different stages,such as investigation,design and construction.The paper analyses CPT application to soil layer classification,performance curve establishment,CPT-SPT relationship determination,quality controling of backfill and inspection of ground improvement.These ideas and scheme shall provide meaning reference for silimar project design and construction especially overseas projecte.