A horse will often refuse to jump because his confidence has not been established. Check that you are not advancing too fast for him. If you are, go back one level and reduce the difficulty. When you are positive that he is jumping positively, gradually increase the difficulty. Many horses take a long time to build their confidence so be patient.?If your horse is still refusing to jump, try having another horse jump on front of him. Horse often learn faster from each other than from humans. Be warned that hitting him with a whip or using spurs too much will probably make the situation worse.