As a fundamental study to control Alopeuclus aequalis Sobol. var. amurensis(Kom.) Ohwi., on dominant weed in barley and dry seeded rice cultivation on paddy fields, several factors which would have closer relations to its germination and emergence, were examined. The results are as follows. The dormancy of seeds were broken at dry-heat treatment of $30^{circ}C$. The germination rate of the seeds was high in order of 15>10>20> $5^{circ}C$ and was very low at more than $25^{circ}C$. The emergence of A. aequalis was influenced little for the light, but had a tendency to be good on the dark condition. The seeds dried on room temperature germinated few but them treated on $30^{circ}C$ for 24 hours were germinated over 80%. The A. aequalis occured few in the saline soil of salt concentration of more than 0.25% and the germination rate of seeds was very low on the over 0.5% solution of NaCl. On the solution of pH 6.0~12.0, the germination was not effected for pH but was very few on pH 2.0. At the paddy-lowland which have cultivated the soybean for three years A. aequalis emerged a few.