Name: Ryo Saito
 Institution: Reserch center for the early universe
 Title: Primordial Black Hole as Source of Boost Factor
 Key Words: Dark Matter; Cosmic ray; Primordial Black Hole
 Abstract: Primordial black holes (PBHs) accumulate WIMPs around them and form ultracompact minihalos (UCMHs), if the WIMP is a dominant component of the dark matter.
We discuss that the UCMHs seeded by the PBHs with sub-earth mass enhance the WIMP annihilation in the present Universe and can successfully explain the positron and/or electron excess in cosmic ray observed by PAMELA/Fermi experiments.