  We use observational data on the large scale structure (LSS) of the Universe
measured over a wide range of scales from sub-galactic up to horizon scale and
on the cosmic microwave background anisotropies to determine cosmological
parameters within the class of adiabatic inflationary models. We show that a
mixed dark matter model with cosmological constant ($\Lambda$MDM model) and
parameters $\Omega_m=0.37^{+0.25}_{-0.15}$,
$\Omega_{\Lambda}=0.69^{+0.15}_{-0.20}$, $\Omega_{\nu}=0.03^{+0.07}_{-0.03}$,
$N_{\nu}=1$, $\Omega_b=0.037^{+0.033}_{-0.018}$, $n_s=1.02^{+0.09}_{-0.10}$,
$h=0.71^{+0.22}_{-0.19}$, $b_{cl}=2.4^{+0.7}_{-0.7}$ (1$\sigma$ confidence
limits) matches observational data on LSS, the nucleosynthesis constraint,
direct measurements of Hubble constant, the high redshift supernova type Ia
results and the recent measurements of the location and amplitude of the first
acoustic peak in the CMB anisotropy power spectrum. The best model is $\Lambda$
dominated (65% of the total energy density) and has slightly positive
curvature, $\Omega=1.06$. The clustered matter consists in 8% massive
neutrinos, 10% baryons and 82% cold dark matter (CDM). The upper 2$\sigma$
limit on the neutrino content can be expressed in the form
$\Omega_{\nu}h^2/N_{\nu}^{0.64}\le0.042$ or, via the neutrino mass,
$m_{\nu}\le4.0$eV. The upper 1(2)$\sigma$ limit for the contribution of a
tensor mode to the COBE DMR data is T/S$<1(1.5)$. Furthermore, it is shown that
the LSS observations together with the Boomerang (+MAXIMA-1) data on the first
acoustic peak rule out zero-$\Lambda$ models at more than $2\sigma$ confidence
limit.
