  We propose novel structure formation scenarios based on a non-singular higher
curvature cosmological model. The model is motivated by the $R^2$ coupling of a
scalar field appearing in the string theory, and in our scenarios the universe
has no beginning and no end. We give two examples with explicit parameter
values which are consistent with present observations of the cosmological
structure. In the first example, the origin of structures are generated as the
adiabatic perturbation during the chaotic inflation, while in the second the
isocurvature non-Gaussian perturbation from the superinflating era is
responsible for the structure. In the second case it is possible to generate
primordial supermassive blackholes whose scale is comparable to what is
expected in the galactic nuclei.
