There exist lots of basic-ultrabasic rock bodies in the Caiziyuan laterite type nickel deposit in Huili County of Sichuan Province. The petrogeochemistry, platinum group elements and Re-Os isotopic geochemistry suggest that the Caiziyuan deposit was derived directly from the mantle, thus belonging to the residual harzburgite at the bottom of the normal ophiolite suite. Caiziyuan ophiolite may be a part of the relics of ancient ocean floor of small ocean basin, implying that Kunyang rift was evolved into small ocean basin where Huili Group was deposited in the late period of Mesoproterozoic.