Abstract: Based on field tests and elastic- plastic FEM, the paper has a comparative study on the bearing capacity per volume of bored- cas-t place piles. The comparative study include equa-l diameter pile and equa-l diameter pile, equa-l diameter pile and tapered pile, tapered pile and tapered pile, equa-l diameter pile and belled pile, belled pile and belled pile. The results show that the bearing capacity per volume of pile is not all higher when its bearing capacity is higher. The bearing capacity per volume of tapered pile and belled pile are comparatively better. The bearing capacity per volume of short and thick tapered pile is better than long and slender tapered pilecs. Expect for especial circumstance, the belled diameter of belled pile and the diameter of equa-l diameter pile should not be big excessively. The rational selection of geometry dimension of pile is essential after the type of pile is confirmed. The measures of pouring slurry in pile end, making pile puncture into better bearing layer, cleaning out sediment of hole bottom can improve the bearing capacity per volume of a pile.