The　photoinduced　magnetization　in　magneto-optical　crystal　terbium　gallium　garnet　(TGG)　is　investigated　by　time-resolved　pump-probe　spectroscopy.　When　the　pump　pulse　is　elliptically　polarized,　the　rotation　signal　and　the　ellipticity　signal　of　the　probe　pulse　are　observed　at　zero　time　delay,　resulting　from　the　optical　Kerr　effect　and　the　inverse　Faraday　effect.　The　direction　of　the　effective　magnetic　field　is　dominated　by　the　helicity　of　the　pump　pulse,　so　the　rotation　signal　and　the　ellipticity　signal　of　the　probe　pulse　can　be　triggered　selectively　by　modifying　the　helicity　of　the　pump　pulse.　The　full　widths　at　half　maximum　of　the　rotation　signal　and　the　ellipticity　signal　both　can　be　as　fast　as　about　500　fs,　which　indicates　that　TGG　crystal　is　expected　to　be　a　candidate　material　of　ultrafast　all-optical　magnetic　switching.