The major character in The Lion, the Witch, and the Wardrobe are the four Pevensie children: Peter, Susan, Edmund, and Lucy. The most predominant of the four, though, are Lucy and Edmund. It is Lucy who first enters the wardrobe and meets Mr. Tumnus the faun. Edmund acts as a foil for Lucy and also enters the wardrobe only to meet the White Witch. Jadis, the White Witch is the self-proclaimed "Queen" of Narnia and acts as the antagonist of the novel. Aslan, the lion, leads Narnia to breaking free from the White Witch's power after he offers himself in sacrifice.
Minor characters include Mr. Tumnus the Faun, Mr. and Mrs. Beaver, Maugrim the Captain of the Witch's Guard, and the Professor who accepts charge of the Pevensie children after their evacuation from London.
You can find excellent descriptions of the characters at eNotes. Just follow the link pasted below. The main characters are the Pevensie children, Aslan, and the White Witch. There are several minor characters.