The steel-pile-soil-system as a mooring dolphin structure is an important element of marine structures. However, the reliability of this system is very difficult to predict due to inherent uncertainties in the marine environment. The objective of this paper is twofold; (i) to investigate the influences of several sources of uncertainties on different limit states of a steel-pile-soil mooring dolphin under axial and lateral loading conditions and (ii) to suggest partial safety factors required for the codified design. In doing so, the response surface method, RSM is used in reliability analysis. A grid of sampling response points is obtained from a realistic built up NLFEM. Then, this grid is used to formulate a response function equivalent to the implicit limit state function With the help of realistic examples, the most important random variables and limit state are identified. For routine design, partial safety factors are proposed.