来用与传统的五点取样法不同的倒置“Ｗ”９点采样法，对黑龙江省北部豆麦轮作区大豆田杂草发生危害情况进行了调查。结果表明，该地区大豆田杂草有１７科４１种。其中阔叶杂草１４科３５种，占８５．４％，禾本科４种占９．８％，鸭跖草科１种，木贼科１种，各占２．４％。相对多度达１０以上的杂草依次为，稗草、鸭跖草、问荆、铁苋菜、香薷、反枝苋，藜、卷茎蓼、苍耳等 ９种。其中前７种相对多度达２０以上，可视为当地大豆田的优势杂草。 In this paper, we used the inverted “W” 9-point sampling method, which is different from the traditional five-point sampling method, and investigated the occurrence of weeds in soybean field in the north of Heilongjiang Province. The results showed that there were 17 families and 41 species of weeds in soybean field in this area. The broad-leaved weeds in 14 families and 35 species, accounting for 85.4%, accounting for 9.8% Gramineae, Commelinaceae 1 species, Equisetum, a species of 2.4%. The relative abundance of over 10 weeds followed by barnyardgrass, Commelina communis, resistance Jing, iron amaranth, Hong Xiang, Amaranthus retroflexus, Chenopodium album, Polygonum, nine kinds of cocklebur. Among them, the first seven species have a relative abundance of more than 20, which can be regarded as the dominant weed in the local soybean field.