Abstract: Atriplex micrantha, an important wild forage germplasm resource in desert regions, has seed dimorphism. It has two types of seeds that are different in shape, size, color and the size of bracts attached to fruits. Small, black seeds with a glossy, smooth testa are covered by extended bracteoles. Brown seeds are relatively larger and covered by bigger, extended bracteoles. Study of the germination phenology and reproduction output from heteromorphic seeds has significant value for understanding mechanisms of adaptation to habitat and the evolution of plant life-history strategies. In the reproduction output study, we selected 3 different micro-habitats (abrupt slope, gentle slope and base of slope) in a low mountain, gravel desert population of Junggar and randomly selected 10 plants of A. micrantha in each habitat to measure plant height, seed output scale and biomass allocation. The results showed: 1) There were significant differences in the sizes of individual plants growing in different micro-habitats. Plants growing at the base of slope were biggest, those in the abrupt slope smallest. 2) The total reproductive allocation and the reproductive allocation of brown and black seeds significantly increased with the increasing size of the individual parent plant. The reproductive allocation of big plants was 57.57%, with the reproductive investment of brown seeds equal to that of black seeds. The main reproductive investment of medium and small sized plants was to the black seeds, with their reproductive allocation less than 30%. 3) With the increase of parent plant size, both the number and the ratio of black seeds outputted by the three plant height grades were significantly higher than those of brown seeds. The ratio of black seeds to brown seeds was 2.16-7.41∶1. The flexible reproductive output of heteromorphic seeds evidence how A. micrantha adapts to harsh desert environments.