Abstract: Fifteen varieties of wheat (Triticum vulgare) were sown in the experimental farm of the Institute of Plant Physiology, Academia Sinica in November 1955. From May to the first part of June 1956, three red and three white varieties were harvested at four stages of maturity (milk-ripe, dough-ripe, waxy-ripe, and yellow-ripe), while the other varieties (3 white and 6 red varieties) were harvested at the yellow-ripe stage only. Germination tests either immediately after harvest or after treatment with various methods were made at given temperature on moist paper in large petri-dishes. The results are summarized as follows. 1. The grains harvested at milk-ripe stage did not germinate at all , but a high percentage of germination was obtained after a two-month storage . Those harvested at dough-ripe, waxy-ripe and yellow-ripe stages showed an increase in the percentage of germination. Higher percentages were found in the white varieties. 2. The effect of desiccation with CaCl2 at room temperature (to moisture content of around 10%) on the germination of grains varied greatly with the varieties and the stages of maturity. Desiccation of grain at the milk-ripe stage showed very little effect , but with grains of other stages, a great increase in germination percentage was achieved. Grains desiccated at 25–30℃ had a shorter dormant period than those desiccated at 4–8℃ . 3. Pre-chilling at 4℃ for 2 days before drying had no effect on the germination percentage of grains harvested at the milk-ripe stage, but a great increase resulted from the same treatment when the grains had been first desiccated. The response to the pre-chilling treatment varied also with varieties. The white varieties showed a higher percentage of germination as the result of she treatment, which, however could bring about no effect on the grains without soaking . 4. All the red varieties except one had a longer dormant period than the white varieties . 5. There was no correlation to have been found between the length of dormancy and the vernalization characteristics in the white varieties, but with the red wheat, the varieties with a longer dormant period belonged to the semi-winter type. 6. An increase in percentage of germination was achieved from the grains stored: at high temperatures (40, 44, 47 ℃) for one week. The grains of the white wheat varieties lost their viability to some extent after bring stored for three weeks at 47 ℃, whereas those of the red varieties remained sound . 7. Fumigation with chloropicrin (80 g per cubic metre) resulted in a loss of viability in the white varieties, but no effect was observed on the red varieties. 8. When separated from the endosperm, the embryo of dormant grain would germinate promptly. The mechanism of dormancy of wheat grain and the sprouting in the ear before harvest are discussed according to the results of the present paper and earlier literature.