Samples of Dalian river sand and calcareous sand in the South China Sea were prepared in various densities through different sampling methods to study the difference of inherent anisotropy.The triaxial apparatus assembled with whole-surface digital image measuring system was adopted in the test.The influence of sample size effect under the condition of confining pressure was also considered.The reliability of the whole-surface digital image measuring system was verified by comparing with true triaxial apparatus.The test results show that the character of inherent anisotropy is different for the same sand made by different sampling methods.The inherent anisotropy of different sands made by the same sampling method also shows a difference because of their unique grain composition.