This study examined the effects of feeding Nile tilapia guar-meal diets on the composition of zooplankton community generated within rearing tanks under the biofloc conditions. The experiment lasted for 70 days for rearing Nile tilapia in biofloc tanks with zero water exchange. Five practical diets were formulated to be isonitrogenous (30% CP) and isocaloric (20 KJ/g diet). Diets were assigned as: diet 1, CTRL or control 0- guar meal, diet 2: SBM50 where 50%  of the soybean meal protein was replaced by guar meal, diet 3: SBM100 where 100% of soybean meal protein was replaced by guar meal, diet 4: FM50 where 50% of fish meal  protein was replaced by guar meal, and diet 5: FM100 where 100% of fish meal  protein was replaced by guar meal. Both control and FM100 treatments recorded the significantly highest (P > 0.05) total zooplankton count. Lecane, Philodina and Vorticella were the most dominant species identified within the zooplankton community of all dietary groups. The total zooplankton count decreased with the increase of guar meal inclusion level in the diet and the opposite trend was shown for Lecane sp. These results indicated that feeding Nile tilapia guar meal-diets significantly affect the zooplankton composition generated within the biofloc rearing tanks. It was concluded that biofloc zooplankton community, as a secondary natural food source, is the best when 50% of the SBM is replaced by guar meal in Nile tilapia feeds.