In order to verify whether there are relevant substances in Jacaranda mimosifolia that can produce the allelopathy to other plants. We studied the allelopathy of the concentration of 0. 001,0. 025,0. 050 g·m L- 1water extract of the flowers of J. mimosifolia for the seed germination and seedling growth,taking the complete single flowers of J. mimosifolia grown in Wenjiang region as materials,the seeds of Lactuca sativa and Festuca arundinacea as receptor materials,and the water treatment as the control CK. ...