Miscanthus has been studied and used for several energy vectors production such as bioethanol. For anaerobic digestion it presents a low methane potential but this potential can be improved either by genotype selection or pretreatment. Eight different miscanthus genotypes belonging to M. x giganteus, M. sacchariflorus and M. sinensis species were studied. In a second time, alkali pretreatments (NaOH 10g 100gTS-1, CaO 10g 100gTS-1) were applied in different operational conditions : temperature, time, solids content, particle size on Flo genotype. The methane potential varied between miscanthus genotypes with values ranging from 166 ± 10 NmLCH4 gVS-1 to 202 ± 7 NmLCH4 gVS-1. Regarding the pretreatments and operational conditions tested in this study, soda is more efficient than the lime. All of the studied pretreatments increased the kinetics and the methane production (from 17% to 121%).