Spin polarization, the difference in the number ofspin-up and spin-down electrons, is an intrinsicproperty of ferromagnetic materials. Materials withhigh spin polarization have important technologicalimplications for magneto-electronic devices, e.g.devices that use magnetic tunnel junctions (MTJ),giant magnetoresistance (GMR) and/or magnetic randomaccess memory, (MRAM). The fundamental physics ofhigh spin polarization materials forms the basis forfuture technological applications.In this work, measurements of spin polarization havebeen performed on c-axis gadolinium and dysprosiumthin films, epitaxially grown on (11-20) sapphiresubstrates with a tungsten (110) seed layer. Thevalues of spin polarization of c-axis epitaxialgadolinium and dysprosium films were obtained usingthe point contact Andreev reflection (PCAR)technique with quantitative analyses.