We　report　a　time-resolved　optic　interferometry　(TROI)　that　enables　to　straightway　probe　the　optical　properties　of　traditional　and　special　thin-film　materials　by　feat　of　a　phase　delayed-interference　between　double　beams　of　femtosecond　laser　synchronously　traveling　through　vacuum　(air)　and　sample,　respectively.　As　a　verification　of　measurement　accuracy　created　by　the　TROI,　the　group　and　phase　velocities　as　well　as　the　refractive　index　of　noncrystal　thin-film　HfO2,　the　crystal　thin-film　materials　YAG　(isotropic　cubic　system),　and　LiNbO3　(aeolotropic　rigonal　system),　are　measured　by　femtosecond　laser　pulse　with　800　nm　central　wavelength.　The　data　exhibit　a　satisfactory　consequence　in　which　even　a　subtle　change　of　measurand　can　be　ascertained　by　manipulating　the　resolution　in　temporal　and　spacial　domains　via　the　delay-line,　whether　the　films　are　isotropic　or　aeolotropic　and　any　different　orientations　of　sample.　Unambiguously,　the　presented　TROI　is　conspicuous　to　the　precision　measurements　of　environment-dependent　and　phase-sensitive　optical　parameters　especially　involved　in　specific　nanoscale　optical　devices　and　structured　layers　or　coatings.