Chemical conditions at the site of calcification of corals play a key role on fast biogenic carbonate accretion, but how it responds to climate change is largely unknown. Here, we present multiple, century-long records of pHcf and DICcf of calcifying fluid (cf) in corals from the South China Sea using the δ11B and B/Ca techniques. The cf chemistry and growth parameters of 6 massive Porites colonies show consistent changes in response to high-frequency climatic oscillations over the past ~550 years, with lower DICcf and growth rate, higher pHcf and Ω cf during colder intervals and vice versa. Inferred from the paired records cf chemistries and growth rates, these tropical corals may have acclimatized and/or adapted a highly variable climate during their long evolutionary history through modulating their cf chemistry to optimize calcification rates. Moreover, SCS corals have taken advantage of global warming and their growth rate has increased substantially since the end of Little Ice Age, and been largely unaffected by ocean acidification so far.