The differences in the solute distribution in microstructure of Pd40Ni40P20 alloy solidified on board a Chinese retrievable satellite and on the ground were studied. In comparison with those crystallized under normal gravity conditions (1 g), it was found that the P content was lower, but the Pd content was higher in the primary phase in microgravity conditions (mu g). In the eutectic region the P content, however, was increased but the Pd content was decreased. The differences in solute distribution crystallized under 1 g and mu g conditions show the influence of buoyancy convection on the mass transport coefficient in liquids under normal gravity conditions.