Geotechnical characterization of soil layers plays an important role on time management, cost and design reliability. Having a comprehensive knowledge of the soil layering, the safety and stability is guaranteed during the longevity of projects. Thus construction problems and consequently the project costs would decrease. Due to high cost of geotechnical investigations for any individual project, a global geotechnical site investigation in a special extended area and forming a data base as an outline for detailed geotechnical studies seems to be valuable from technical and economical aspects. This study is standing for assessment of geotechnical properties of Iran north coastal grounds. In most cases, characteristics of whole coastal strip were described, however, due to highly extended area with more than 600 km of coastline only a limited strip of 0.7 km width, 100 km length was selected for this study. The area was mostly located in the west of Mazandaran province and a small section of eastern Guilan. The investigations included of assessment of the area general characteristics which were effective on the geotechnical problems and representative of types, physical and mechanical parameters of the area soil layers as well as underground water conditions. Several important projects affected by those characteristics and require special measures were then introduced. Moreover, detailed description of soil layers and ground water conditions were also presented. Besides the soil physical properties such as natural water content, unit weight, Atterbe rg limits, the trend and range of their variations in the study area were evaluated. The mechanical properties of soil layers were also considered. In this context, the SPT of soil profiles was investigated. The soil relative density, internal friction angle, shear wave velocity and stress-strain modulus of granular soils were then investigated based on the SPT data. Several correlations were developed between N SPT and some of the soil parameters. In most cases, descriptive statistics was applied on soil parameters to demonstrate the range of variability of soil parameters regardless of soil position or layering. To demonstrate the trend of variations of soil properties in the whole study area, 12 sub-region were defined by taking only geographical boundaries into account to consider the variability of soil characteristics from one location to another. In fine grained soils, sensitivity, swelling and shrinkage potential were then assessed. To present the statistical variations of several soil parameters such as cohesion, undrained strength and compression index, the relationships between these parameters and N SPT , were also considered. To cosider the soil performance, the behavior of all soil types (based on the unified kashida; TEXT-ALIGN: justify; TEXT-KASHIDA: 0%; TEXT-INDENT: 0in; MARGIN: 0in 0in 10pt; unicode-bidi: embed; DIRECTION: ltr" dir=ltr Keywords: Geotechnical Properties, Coastal Grounds, Construction Problems, Statistical Analysis, SPT, Correlations.