Comprehensive geotechnical data including lab testing,in-situ CPT testing and foundation installation records have been collected and studied from numerous offshore oil and gas projects developed so far in the northern region of South China Sea.It indicates the physical properties and mechanical properties of the cohesive sediments from the vast shallow water regions in the study area are consistent themselves but obviously different from that from the deep water regions,while the latter behaves similarly to the "standard API" clay most commonly found in the Gulf of Mexico and West Africa.The cohesive soils from the shallow water regions are very low in both plasticity index and clay composition,and more importantly they have a normalized CPT friction ratio only about 1/3 of the typical value found in other areas while no obvious difference was found in the normalized bearing and pore water pressure properties.The above observation is immediately related to the fact that the driven pile in the region often encounters much less resistance during installation if the conventional method is used.Then the CPT based method was developed for the pile driving analysis which fully appreciates the CPT friction characterizations and ended with excellent agreement with the field measurements.