Takayuki Ushikubo spends much of his time researching Geochemistry, Isotopes of oxygen, Chondrite, Chondrule and Mineralogy. His study in the field of Zircon is also linked to topics like Sulfate. Takayuki Ushikubo studies Oxygen isotope ratio cycle which is a part of Isotopes of oxygen.

His Chondrite study deals with the bigger picture of Meteorite. His Chondrule study incorporates themes from Protoplanetary disk, Formation and evolution of the Solar System and Olivine. His work on Microprobe as part of general Mineralogy research is frequently linked to Faraday cup and Secondary ion mass spectrometry, bridging the gap between disciplines.