Ecotone is zones of transition between adjacent ecological systems, having a set of characteristics uniquely defined by space and time scales and by the strength of the interactions between adjacent ecological systems. It situated where the rate and the dimension of ecological transfers (solar energy, nutrient exchange) have an abrupt change. Ecotonal ecosystems are characterizes by (1) permeability and vector diffusion;(2) semi-permeable membranes function and modification;(3) relative high instability and volatility;(4) a wider amplitude of fluctuating physical and biological processes in arid zone ecosystems;(5) critical threshold. Ecotones of desert-oasis exist at every scale. The structural variables important to ecotones are size, shape, biological structure, structural constraint, internal heterogeneity, ecotone density, fractal dimension, patch diversity and mean patch size. The function of ecotones among desert and oasis are stated, such as passive diffusion, active diffusion, probability of edge encounter and probability of crossing a boundary. The important functional variables are stability, resilience, energetic, functional contrast and porosity. Finally, the future directions for the research of ecotone among desert and oasis are also presented.