The present study was carried out in order to identify the ant fauna and her potential role as auxiliary of an agricultural system based on cocoa trees leeched by Loranthaceae, in Nkolbisson neighborhood in Yaoundé (Cameroon). The work was conducted from May to September 2015. An inventory of all woody species and the associated ant fauna was carried out beforehand, followed by an inventory of the ant fauna associated couples Theobroma cacao/Loranthaceae during periods of non-flowering, flowering and fruiting Loranthaceae. We inventoried a total of 187 plants of which 44 (23.53%) were parasitized by flowering-shrub epiphytes (Loranthaceae). Theobroma cacao (cocoa) appeared to be the most abundant species (122 plants) followed by Dacryodes edulis (16 safou trees) and Mangifera indica (15 mango trees). Three species of Loranthaceae were identified: Tapinanthus preussii (Engler) Van Tieghem and Phragmanthera capitata (Sprengel) S. Balle which both attack Theobroma cacao (cocoa tree) and Tapinanthus bangwensis (Engl.et. Krause) Denser which attacks mainly forest type trees. Five sub-families of ants (Pseudomyrmicinae, Dolychoderinae, Ponerinae, Formicinae and Myrmicinae) divided into 16 genera and 35 species were recorded throughout the agrosystem. Tetramorium acculeatum has emerged as the most dominant ant species on both T. preussii and P. capitata. Monitoring of the ant foraging activity during flowering and fruiting Loranthaceae shows they participate in the flowers fall.