In order to understand the water absorbance features of mucilage on the seeds of Plantago minuta Pall. and the role of the mucilage in adaptation of the seed to drought edaphic condition during germination stage, the physical feature related to water absorption of the mucilage, percentage germination of the seeds with or without mucilage in a range of iso-osmotic PEG(-1.54--11.54MPa) solution were tested under controlling condition. The results showed that the weight of mucilage was 5.6% of the weight of seeds, and the mucilage was able to absorb an amount of water of 217 times of its own dry weight. In deioned water, the water absorbance of the seeds with mucilage was increased from 2 times to 14 times due to the mucilage materials, indicating a role of the mucilage in keeping sufficient water for germination. Furthermore, water absorption of the mucilaginous seeds reached saturation in 2 hours after being submerged in deioned water, and the water saturated seeds were dehydrated to their original dry weight in 48 hours after being exposed to air at room temperature. Third, the germination potential on the 3rd day and the total percentage germination on the 10th day of seeds with mucilage were significantly greater than those of seeds without mucilage under mild osmotic stress PEG solution (-0.33--015MPa) or deioned water conditions. Under stronger osmotic stress (-1.15--0.73MPa), the germination potential on the 3rd day for mucilaginous seeds was significantly lower than that of the seeds without mucilage. There was no significant difference in total percentage germination on the 10th day between the seeds with and without mucilage. These results indicated that mucilaginous material on the seeds of Plantago minuta Pall. might absorb water from the seeds instead of from PEG solution under drought condition, which resulted in detainment of the seed germination. It is concluded that mucilaginous materials on the seeds of the plant plays a role in regulating seed germination by adjusting water acquisition of seeds in desert habitat where soil moisture fluctuates violently in early spring. Such strategies may help the plant to avoid the risk of drought stress or even extinction of the population brought by coinstantaneous germination of a large proportion of seeds.