The　objective　of　this　paper　was　to　optimize　the　flocculation　and　biomass　productivity　of　Botryococcus　braunii　by　using　an　organic　carbon　source　glycine.　The　effects　of　culture　period　and　glycine　dose　with　high,　medium　and　low　levels　on　both　solid　concentration　achieved　and　biomass　productivity　were　conducted.　It　was　found　that　extracellular　polymeric　substances　(EPS),　which　promotes　flocculation,　was　produced　not　only　by　bacterial　but　also　by　microalgae.　The　productivity　of　EPS　was　affected　by　culture　period,　glycine　dose　and　mixing　time.　The　maximum　EPS　of　103.3　mg/L　obtained　with　11　day　culture　period　and　0.1　g/L　glycine,　leading　to　the　maximum　solid　concentration　achieved　of　51　g/L,　the　biomass　recovery　rate　72.　©　(2014)　Trans　Tech　Publications,　Switzerland.