A continuous variable valve duration apparatus may include: a camshaft; first and second cam portions on which a cam is formed respectively; first and second inner brackets transmitting rotation of the camshaft to the first and second cam portions respectively; a slider housing in which the first and the second inner brackets are rotatably inserted; first and second guiding portions formed on the slider housing; a control shaft parallel to the camshaft; a control rod eccentrically formed on the control shaft; a guide head on which a head guiding portion and a head hole are formed; a cam cap supporting the control shaft; a cam cap guiding portion mounted to the cam cap; and a control portion selectively rotating the control shaft such that the slider housing is moved along the cam cap guiding portion.