Provided is an optical image stabilizer for a camera module assembly including at least one or more guide portions for guiding linear movement while preventing friction in first and second drive portions. The optical image stabilizer includes a first drive portion including a tip provided between a housing and a first drive plate to drive the first drive plate in a first direction, a second drive portion including a tip provided between the first drive plate and a second drive plate to drive the second drive plate in a second direction, and first and second guide portions formed in the first and second drive plates in positions corresponding to the tips of the first and second drive portions such that the first and second guide portions guide linear movement of the tips and prevent friction when the first and second drive portions are driven in the first and second directions.