The high-density shielding materials containing higher percentage (>80%) of BaSO4 have been developed and their gamma-ray attenuation parameters have been investigated. Three samples have been prepared [Sample-1 (83.75%), Sample-2 (84.75%), and Sample-3 (82.75%)], their elemental composition has been determined by the EDX method, and the density has been measured experimentally for Sample-1 (3.362 g/cm3), Sample-2 (3.365 g/cm3), and Sample-3 (3.358 g/cm3). The mass attenuation coefficients (μ/ρ) have been calculated analytically in order to generate a database for the photon energy range from 1keV to 100MeV using WinXcom software. For validation, this parameter has been measured experimentally for gamma-ray emitted from 133Ba radioactive sources using HPGe detector (with relative efficiency ≈20% relative to a 3"×3"NaI(Tl) detector, and resolution 2.3keV at 1.33MeV γ-lines). The linear attenuation coefficient (μ), total atomic cross section (σa), total electronic cross section (σe), effective atomic number (Zeff), effective electron density (Neff), and relaxation length (λ) have been calculated for the same energy range. All parameters have been compared with the values for five different concretes namely barite, serpentine, ilmenite-magnetite, ordinary concrete, and basalt-magnetite. Transmission graphs have been drawn for some widely used radioactive sources. Sample-2 with the highest density (3.365 g/cm3) and comprising relatively higher atomic number elements is found to be the most effective shield for gamma-ray attenuation.