Abstract: Viewing from the aspect of parameter identification,the parameters of coordinate translation,rotation and the standard curved surface equation are to be estimated. Genetic algorithms have particular advantages in this field. A series of modifications are made aiming at several defects of the classic simple genetic algorithms,and an improved algorithm is realized using MATLAB. Both algorithms are used many times in an engineering examples and a simulated complex surface example,and the calculation results are compared. Applications and comparisous show that the genetic algorithm can be well used in the field of spatial surface fitting,and the improved algorithm is better.