Donald (1968) proposed the general term "ideotype" as a biological model that performs or behaves in predictable manner in a given environment. The definition of "ideotype" is widely considered as a combination of genotype and phenotype. In water-deficit environment, crop ideotype as a plant model is mainly expected to yield a great quantity of grain or other useful product. The selection for crop ideotype is an important prerequisite for water-saving cultivation and high-yield breeding program in dryland wheat (Triticum aestivum L.). It is widely based on "defect elimination" or "selection for yield" under drying environment. The valuable additional approach is available through the breeding of model characteristics known to influence photosynthesis, growth and grain production. This paper summarizes the evolution history of plant type for dryland wheat and its regulatory mechanism according to four components including root type, stem type, leaf type and spike type, based on several critical criteria including yield formation and drought adaptation under population conditions. Dryland wheat ideotype aims to minimise demand on resources per unit of dry matter produced. Over the long evolutionary course from wild diploid and tetraploid, to modern hexaploidy varieties, the wheat has been evolving from the weed type of "high root to shoot ratio, low harvest index, high canopy/height ratio, small spike and prolate seed" to the crop type of "low root to shoot ratio, high harvest index and high grain-leaf ratio and small canopy/height, large spike and grain number". Considering the evolutionary rules of plant type components, the structure and function of the major organs have been increasingly strengthening in dryland hexaploid wheat. Root type is mainly developing towards moderate root system size, more root number and higher root physical vigor; stem type is concentrated on the length ratio of stem internode approaching "golden section", and the plant height is kept on the ideal value of 80-100 cm. Leaf type is mainly featured by erect leaf, moderate aspect ratio of flag leaf, and backward second leaf to maintain about 20 cm as the moderate length. Spike type has been evolving towards erect spike, large spike and more seeds per spike. The number of tillers per plant tends to reduce, and plant architecture is becoming more compact. These criteria are to be satisfied especially under the conditions of high density of population. Dryland wheat has gone through double pressures including natural selection and artificial selection, in which the structure of plant architecture is conducive to increased population yield and water use efficiency, and accordingly obtains higher population fitness. According to Nicholson (1962), natural selection may be seen to operate through two mechanisms: environmental selection and competition. Modern dryland wheat as annual seed crop has experienced long-term artificial selection pressure, which contains a variety of modifications on morphological characters mainly including tallness, leafy canopy, tillering and root characters. However, the design of dryland wheat ideotype is likely to involve concurrent modification of the criteria mentioned above. Therefore, the wheat ideotype described here will call for consideration of the density of planting, dry matter distribution model and weak community competitiveness.