For proper partitioning of chromosomes in mitosis, the chromosomal passenger 
complex (CPC) including Aurora B and survivin must be localized at the center of 
paired kinetochores, at the site called the inner centromere. It is largely 
unknown what defines the inner centromere and how the CPC is targeted to this 
site. Here, we show that the phosphorylation of histone H3-threonine 3 (H3-pT3) 
mediated by Haspin cooperates with Bub1-mediated histone 2A-serine 121 
(H2A-S121) phosphorylation in targeting the CPC to the inner centromere in 
fission yeast and human cells. H3-pT3 promotes nucleosome binding of survivin, 
whereas phosphorylated H2A-S121 facilitates the binding of shugoshin, the 
centromeric CPC adaptor. Haspin colocalizes with cohesin by associating with 
Pds5, whereas Bub1 localizes at kinetochores. Thus, the inner centromere is 
defined by intersection of two histone kinases.