<p>²¹²Bi is a promising radionuclide for targeted alpha therapy (TAT), necessitating accurate activity determination for its safe and effective application. This study utilizes two features of liquid scintillation (LS) counting instrument- alpha/beta separation and Cherenkov counting for measuring ²¹²Bi activity. A radiochemical purification method for ²¹²Bi was developed, and the practicality of using liquid scintillation (LS) for alpha/beta separation was confirmed. The factors affecting the alpha/beta separation in LS counting were investigated. Under optimized conditions, the alpha and beta signals were distinctly separated, achieving a Figure of Merit (<i>FOM</i>) of 1.44, with an activity measurement uncertainty for ²¹²Bi of 1.5% (<i>k</i> = 2). Additionally, a Cherenkov counting method was developed, with counting efficiency corrected using the Triple-to-Double Coincidence Ratio (TDCR) technique. A strong correlation between counting efficiency and TDCR values was observed. Both methods offer reliable, on-site assay options for ²¹²Bi measurement in radiopharmaceuticals.</p>