Abstract:In order to demonstrate the application value of florasulam in wheat field in northern China, the spectrum of weed control, herbicidal activity and the safety to common various wheat varieties of florasulam which belonged to triazolo [1,5-c] pyrimidine-2-sulfonanilide herbicides were studied in the laboratory. The results indicated that florasulam had a wonderful herbicidal activity to common broadleaf weeds in wheat field, and there was higher biological activity against Descurainia sophia, Silene conoidea, Lithospermum arvense, Galium aparine and Capsella bursa-pastoris than tribenuron-methyl with the activity ratio of 1.56, 6.26, 1.65, 18.27 and 22.75. The tolerance of Jinan 17 and Shanyou 2 to florasulam were 2.57 and 11.66 times more than tribenuron-methyl respectively. There was better selectivity to florasulam between wheat and weed (selectivity index 11.16-49.32) than tribenuron-methyl. In seedling stage, plant length and fresh weight were inhibited when wheat was treated with florasulam and the inhibition to various wheat varieties was significantly different, the inhibition ratio to Linmai 2, Jining 13 and Jinan 17 was relatively higher and the lower was Weimai 8, Shannong 6 and Taishan 9818. In conclusion, florasulam has an excellent application prospect.