Abstract: The present paper deals with a survey of the vertical distribution of rice varieties in Szemao region which is situated at southwestern Yunnan. The main results obtained are summarized as follows: 1. In Szemao region, the vertical distribution of "Hsien" and "Keng" is very prominent. In general, below the altitudes of 1,400 m there is what the masses call "Hsien" belt where "Hsien" varieties are cultivated while over 1,800 m there is "Keng" belt and between 1,400 m–1,800 m. there is the mixed belt of the two. This succession of the "Hsien" and "Keng" varieties caused mainly by the ascendence of altitude is shown by the number of varieties and their cultivated area respectively. 2. With the ascending of the altitude the height of the plant is reduced, the leaves become shorter, the hulled and unhulled grains are shorter and narrower, the color of lemma-palea looks deeper, and the color of pericarp changes from white to red. 3. According to our survey at the mixed belt of "Hsien" and "Keng", we found that some varieties have characteristics of both "Hsien" and "Keng" thus making them difficult to define in classification. 4. We have collected 74 upland varieties with glabrous spiklets in this region. Through careful examination we recognized that they belong to "Keng". In the classification of rice varieties the shape of the sterile glume was somehow neglected. After comparison among our material we found that the shape of sterile glumes is a variable character. The margin of the sterile glume in the different varieties may be entire, undulate, dentate, lobed and deep-lobed. The sterile glumes of some varieties are glabrous and others hairy. It seems to us that the shape of sterile glume may more or less be a worthy character in the classification of cultivated rice varieites.