To intensively study the responses of single piles under combined vertical and lateral loads,the common form of the coefficient of subgrade reaction was introduced.The semi-analytical solutions were obtained by dividing the pile shaft under ground into many small segments and supposing the axial force of the pile and the coefficient of subgrade reaction corresponding to each segment to be constants.Together with the pre-existing power series solutions for the pile shaft above ground,the relevant computer program was developed by Fortran programming.The calculation results indicate that the maximum lateral displacement and bending moment increase significantly with the increase of lateral loads.The vertical load can cause the instability of the pile.The soil resistance at the ground surface and the distribution of the coefficient of subgrade reaction along depth play important roles in pile responses.The computed results obtained using solutions corresponding to a special case agree well with those obtained using pre-existing solutions,meaning that the presented solutions are dependable.