  We propose a morphological multi-scale analysis of large-scale structures
obtained by computer simulations and by observations. Structures are obtained
at different scales by applying a wavelet transform on the observed and
simulated data. Application of a segmentation algorithm allows a quantitative
morphological description of the structures at each scale. The morphological
parameter which we propose represents the deviation of a structure from
sphericity. The dependence on scale of this simple parameter is shown to
characterize in simulations the underlying cosmological model. We compare the
HDM, CDM and mixed models with the CfA catalogue. This comparison favours a
mixed model containing $65\%$ of CDM, $30\%$ of HDM, and $5\%$ baryonic matter.
