Data on the rapid, elemental and calorimetric analysis, such as ash melting behaviour and thermogravimetric profiles of six Cuban biomass feedstock are shown, in order to assess their potential for bioenergy production. The studied biomasses are Jatropha curcas husk, Moringa oleifera husk, Dichrostachys cinerea, Ulva lactuca, Chaetomorpha gracilis and Sargassum fluitants. Seed, kernels or stems and algae were characterized by weight. Sample preparation and tests were established according to referenced German standards with particle size <75 mm. In addition, thermogravimetric analyses have been performed at 10 °C/min in Argon atmosphere. Data in the paper are shown in Tables and Graphs. The data represent valuable information for simulation or further implementation of gasification or pyrolysis processes using these biomasses. Keywords: Biomass, Gasification, Pyrolysis, Ash melting behaviour, Thermogravimetric analysis