A single crystal Ni3Al-based superalloy was successfully fabricated by liquid metal cooling (LMC) process. The  and  oriented samples were prepared using the seeding technique. The microstructure evolution during heat treatment was investigated. The tensile and high-temperature creep rupture properties were studied both before and after the heat treatment. The microstructure evolution during creep was also studied intensively to figure out the deformation mechanism of crystals with different orientation. The results showed that the mechanical properties and deformation mechanism were strongly affected by orientation. The rupture life of samples with  orientation was five times longer as that of the samples with  orientation.