In this study, the flocculation process of Chlorella vulgaris and Rhodotorula glutinis induced by inorganic salts modified montmorillonoid was conducted. The maximum flocculation efficiency (FE) of 98.50% for C. vulgaris and 11.83% for R. glutinis were obtained with 4 g/L and 5 g/L flocculant within the dosage scope of 1-5 g/L. The difference of FE was then thermodynamically explained by the extended DLVO theory and the FE of R. glutinis was mechanically enhanced to 90.66% with 0.06 g/L cationic polyacrylamide (CPAM) at an optimum pH of 9. After that, aimed to utilize the remainder flocculant capacity, C. vulgaris culture was added to the aggregation of R. glutinis. Fortunately, the coagulation of R. glutinis and C. Vulgaris was achieved with 0.05 g/L CPAM and 5 g/L flocculant at pH 9 and the FE reached 90.15% and 91.24%, respectively. (C) 2016 Elsevier Ltd. All rights reserved.