15at.%Yb3+:Gd2SiO5 crystal with a size of30 mm75 mm is grown by the Czochralski method, and its lattice parameters, atom coordinates and temperature factors are determined by the full-profile Rietveld refinement method. Its spectral parameters of oscillator strength, line strength, transition probability, energy lifetime and integral emission cross-section for Yb3+2F7/22F5/2 transition are calculated using the absorption spectraum. And the laser performance evaluation shows that this crystal is a potential laser crystal with relatively high threshold, and could be used as a medium of tunable or ultra-fast laser pumped by high-power laser diode.