Boron isotopes analysis in marine biogenic carbonates have witnessed a remarkable increase in recent decades due to its application as a proxy for reconstructing ocean pH and atmospheric CO2 levels. However, accurate and precise determination of boron isotope compositions, particularly in marine biogenic carbonates with low boron concentrations is challenging. In this chapter, we have provided a detailed overview of various methodologies available for sample processing, strategies for minimizing blank contributions, techniques for chemical purification, and available analytical methods. Our discussion is focused on several key aspects such as sample requirements for boron isotope analysis, precision and accuracy of the measurements, advantages/disadvantages inherent in each approach for the separation and purification of boron. Furthermore, we delve into an in-depth discussion of existing standards and their reported values, with a primary focus on boron isotope analysis using Multi-Collector Inductively Coupled Plasma Mass Spectrometry (MC-ICPMS) and its application as a proxy/tracer in paleoceanography and paleoclimate studies. Despite notable advancements in methodologies, techniques, and technological innovations, there remains a pressing need for further enhancements to reduce sample requirements, improve precision, and expand the availability of standards suited to diverse matrix compositions. We anticipate continued progress and more insights into the application of boron isotopes in the earth, ocean, environmental, and planetary sciences in the foreseeable future.