Abstract Creation of the biological tissue phantoms especially breast tissue cancer in the terahertz frequency range is an actual problem of medical physics. This paper suggests using soy protein as one of the main component of breast tissue phantom instead of gelatin, as it’s water-and fat-holding substance, “quasi-bioidentical” to animal proteins and their chemical characteristics are stable in time. Implemented phantoms were analyzed experimentally by using terahertz pulsed spectroscopy, obtained results were compared with spectra of adipose, fibrous and cancer tissue (human female breast tissue).