Operating system based on microkernel architecture has high adaptability and toughness. Otherwise, multi-core processor appeared by progress of LSI technology. If it is made to run OS based on microkernel architecture and OS server can be distributed to each core on the multi-core processor, load balancing of OS processing will become possible. For the above reasons, the load balancing of OS processing can offer large transaction processing effectively on the multi-core environment. This paper shows the result of evaluations for performance of distributing OS processing in the AnT operating system based on microkernel architecture works on the multi-core environment. To put it concretely, this paper shows the difference in the performance by distributed forms at the time of data reference in a block unit. Moreover, this paper shows the distribution effect by distributed forms using PostMark and Bonnie.