The aim of this thesis was the development of the study of lacunary interpolation by spline functions and their applications by changed the boundary condition for quantic and sixtic spline functions, and the algorithm was used to find the new absolute error between the original function and the spline function, and also the error bounded between the derivatives of original function and the derivatives of spline functions. Firstly, the object of this work is to show that the change of the boundary conditions and the class of spline functions have effect on minimizing error bounds theoretically and practically, and for application, the )NEB( algorithm was used. Secondly, in this study, (0, 4) lacunary interpolation was generalized by quantic spline function to obtain, the existence, uniqueness, and error bounds for the generalized (0, 4) lacunary interpolation by quantic spline. Finally, the lacunary interpolation problem consisted of finding the sixth degree spline of deficiency four, interpolating the data given on the function value with first and fourth order in the interval [0,1]. Also, an extra initial condition was prescribed on the second derivative of the functions.