According to the standard and manual in the American and European countries, corrected SPT N60 is used to obtain the parameter for soil and (N1)60 is used to obtain the parameters and determine the liquefaction for sand. According to the port project in Venezuela, the SPT method according to ASTM and the corrected SPT method are introduced. The factors influencing the SPT correction are also analyzed. N60 is mainly influenced by energy correction factor CE, and when the soil locates more than 10 m, the N60 is usually more than the original value Nm. (N1)60 is corrected upon overburden factor CN based on N60, for the top layer sand, (N1)60 is usually more than the original value Nm and the lower layer (N1)60 is usually less than the original value Nm. Compared by several methods, the undrained shear strength Cu for a certain over-consolidated clay , with SPT values between 15 and 50 blows and with little coarse grains, can be derived by N60 , which is confirmed to be reliable.