Provided is an exposing method using a variable shaped beam that may minimize a critical dimension (CD) distribution and a mean to target (MTT) difference generated during a process by correcting CD linearity of the design CD of a circuit pattern, and a pattern forming method using the exposing method. In the exposing method, a determination is made as to whether the design size of a beam shot used to expose a circuit pattern is less than a value, or greater than the value. If the design size is greater than the value, the size of the beam shot may be linearly corrected. When the design size is less than the value, the size of the beam shot may be non-linearly corrected.