A morphological study of the human ventricular fold was conducted with special reference to age-related changes and sex differences. The laryngeal specimens examined were obtained from 54 autopsy cases consisting of 27 males and 27 females ranging in age from 20 to 79 years. Each specimen was frontal-sectioned between the anterior and posterior ends of the ventricular fold to yield 8 equal portions. The surface of the entire ventricular fold was reconstructed based on examination of all of the sections, and extent of squamous metaplasia was 3-dimensionally evaluated and expressed in the form of a histological map. In the cases in which smoking history was ascertained, extent of squamous metaplasia was evaluated by the same method. In all of the cases the distribution of the different types of tissues such as glandular, adipose and connective, was examined in the midportion of the specimen (section No. 5). The following conclusions were drawn as a result. 1. The development of squamous metaplasia reached a peak in the middle-age group, particularly in males. The 3-dimensional extension of metaplasia was classified into 4 patterns, however, there were no age-specific differences in pattern, and the posterior-dominant-type and widespread-type were the most common in all age groups. The extension of metaplasia varied with smoking history, suggesting that smoking promotes the extension of squamous metaplasia. 2. Glandular tissue decreased with age, more markedly in females. The distribution of the glandular tissue was classified into 4 patterns. Atrophy of glandular tissue with age occurred in the central area of the ventricular fold, extending to the marginal portion. 3. Collagen fibers decreased slightly with age. Elastic fibers appeared frequently in the lateral portion near the laryngeal ventricle in the aged group.