A kind of loop function LoopN in Genetic Programming (GP) isproposed. Different from other forms of loop function, such as While-Do and Repeat-Until, LoopN takes only one argument as its loop body and makes its loop bodysimply run N times, so infinite loops will never happen. The problem of how to avoidtoo many layers of loops in Genetic Programming is also solved. The advantage ofLoopN in GP is shown by the computational results in solving the mower problem. Different from other forms of loop function, such as while-Do and Repeat-Until, LoopN takes only one of the arguments as its loop body and makes its loop bodysimply run N times, The problem of how to avoid many layers of loops in Genetic Programming is also solved. The advantage of Lobo in GP is shown by the computational results in solving the mower problem.