The fruit and seed characteristics were observed on Atriplex micrantha C. A. Mey. from Junggar desert．It is found the fruits of Atriplex micrantha have dimorphism. It has two types of fruits that are different in shape，size，color of seeds and size of bracts attached fruits．Small, black, lens-shaped achenes with a glossy, smooth testa are covered by extended bracteoles. Brown achenes are rather large and covered by extended bracteoles that are bigger. The fruits (seeds) of Atriplex micrantha were germinated for 15 d in incubators with a 12 h photoperiod and 12 h thermoperiods (dark/light) of 5/15 ℃, 5/25 ℃ and 15/25 ℃. The mature brown seed can germinate in the 3 thermoperiods, and the germination percentage and germination rate of seeds is the highest at 5/25 ℃ (dark/light). Low night (5 ℃) and high day (25 ℃) temperature regimes showed higher germination for black seeds, while at 5/15 ℃ and 15/25 ℃ , germination percentage was low (＜20%). Black seeds have non-deep physiological dormancy; they germinate slowly and to a low percentage. Two weeks of cold stratification, scarification of covering layers (pericarp and seed coat) can increase seed germination percentage and germination rate. The salt concentration in bracteoles of freshly ripened fruits is too low to mediate an inhibitory effect on germination of brown seed. Seed dimorphism may allow Atriplex micrantha to survive in harsh desert habitats.