Anselm was the founder of the ontological argument. He was famous for his ontological argument, but was also misunderstood because of it. In order to rectify those misinterpretations, this paper focuses on his ontological argument, putting forward the author's own opinions on four related issues: (1) whether there are two versions of Anselm's ontological argument; (2) the relationship between his ontological argument and the question whether existence is a predicate; (3) the significance of faith in Anselm's ontological argument; and (4) the relationship between Anselm's ontological argument and the modal ontological argument.