Some ındigenous arid plants* namely E. Lactea, E. Nubica, E. Mau- ritanica, E. Neriifolia, E. Synadenium grantii and E. Psedocactus from the Euphorbeacea family and Procera, from the Calotropis Asclepiada¬ceae were dried and extracted aiming at petrol substitute. The analytical data, i.r., n.m.r., catalytic cracking and chromatographic separation as well as the calorific value were determined.