The time-dependent molecular motions were observed by infrared polarization technique for wood components strained parallel to the fiber axis. A two-stage molecular motion involving three wood components, cellulose, hemicellulose, and lignin, is suggested as the course of wood molecular relaxation. The first stage begins at equilibrium, when a specimen is not stressed, and extends immediately to a minimum dichroic ratio (A⊥/A∥) of carbohydrate components represented by 1160 cm−1 (cellulose) and 1730 cm−1 (hemicellulose) bands, and the maximum dichroism of 1500 cm−1 (lignin). The second stage starts at the end of the first stage and extends to equilibrium recovery. Regardless of the form of external excitation (creep or stress relaxation), or the time of excitation (ramp- or step-loading), the basic two-stage molecular motion pattern was followed, while damping of the molecules accompanied the whole rheological process. The pattern of molecular motion for a wood component is a compensatory result of the interaction of all components. Removing one or more wood components changes the motion patterns of the remaining components. The response of cellulose in a specimen without the presence of lignin and hemicellulose is comparable to that of the other synthetic linear polymers.