  We carry out the determination of the amplitude of relic gravitational waves
power spectrum. Indirect best-fit technique was applied to compare
observational data and theory predictions. As observations we have used data on
large-scale structure (LSS) of the Universe and anisotropy of cosmic microwave
background (CMB) temperature. The conventional inflationary model with 11
parameters has been investigated, all of them evaluated jointly. This approach
gave us a possibility to find parameters of power spectrum of gravitational
waves along with statistical errors. The main result consists in following:
WMAP data on power spectrum of CMB temperature fluctuations along with LSS data
prefer model with small amplitude of tensor mode power spectrum, close to zero.
The upper limit for its amplitude at quadupole harmonics T/S=0.6 at 95% C.L.
