This thesis work was accomplished in the country property Miraflores belonging's space to University National of San Martín, in Low May's, Provincia and Departament San Martín's, Perú. Geographically you coordinate them characterized to show: Length west with 76; Southern Latitude 6. The most suitable density was evaluated for the production of biomass in the caupí cultivation I treatment to quantify the fixation of carbon and by means of the molecular relationship of it formulates it of the photosynthesis, to find the quantity production of CH20, liberation of 02 and the requirement of water far this process. Also, of sorne characteristic biometric of the plant .and the economic analysis of profitability. The statistical design was DBCA with 4 repetitions and 6 treatments, each parcel it was evaluated, whose aftermaths they were analyzed by means of Varianza's Analysis and DUNCAN'S ...