Abstract: The cochineal(Dactylopius confusus) were cultured on cacti collected from ten different counties and the anatomical structure and nutritional components of cacti were analyzed to study the relationship between cochineal and cacti.The results showed that cochineal could host on Opuntia ficus-indica, Opuntia tuna, and Opuntia stricta,but it grew best on Opuntia ficus-indica,and in the species Opuntia ficus-indica,cochineal grew on cacti that imported from Peru and native cacti in Lufeng County of Yunnan Province were better than that of growing on other cacti, and the cochineal grew on spineless cacti were better than that of growing on spinous cacti. The thicker the epiderm of cacti, the worse the cochineal grew. The cochineal could stimulate development of vascular bundle of cacti. Protein and water content of cacti had significant influence to cochineal growth.