A valve train includes a primary rocker arm 50 which is oscillated about a primary oscillating center line L4 by an inlet cam 21, a secondary rocker arm 60 which transmits a valve drive force F1 to an inlet valve 14 and oscillates about a secondary oscillating center line L5, and a holder 30 which supports the primary and secondary rocker arms 50, 60 in such a manner that the primary and secondary oscillating center lines L4, L5 rotate together therewith. As the holder 30 approaches an oscillating position where a valve operating property is obtained where a maximum lift amount becomes maximum, an abutment position P1 where a cam lobe portion 21b abuts with a roller 53 of the primary rocker arm 50 approaches a specific straight line L10 which passes through a holder oscillating center line L3 and a rotational center line L2 of the inlet cam 21.