In　this　paper,　the　far-field　characteristic　of　the　vertical-cavity　surface-emitting　laser　(VCSEL)　incorporating　a　high-contrast　subwavelength　grating　(HCG)　is　analyzed　by　finite-difference　time-domain　(FDTD)　method.　Full　three-dimensional　simulations　are　carried　out　by　utilizing　FDTD　solutions　software.　We　study　the　parameters　of　HCG　made　from　GaAs/AlOx　which　is　defined　by　wet　oxidation　of　an　Al0.98Ga0.02As　spacer　layer.　We　have　simulated　HCG-VCSELs　with　different　HCG　periods　and　oxide　aperture　diameters.　Various　far-field　patterns　including　single-lobe,　double-lobe,　triple-lobe　shapes　are　obtained　with　the　designed　HCG-VCSEL.　More　interestingly,　by　tuning　the　HCG　periods　and　the　oxide　aperture　diameter,　the　far-field　emission　patterns　transform　from　double-lobe　to　single-lobe　shapes.　By　proper　design　of　the　two　parameters,　one　can　obtain　Gaussian-like　beam　outputs,　double-lobe　or　multi-lobe　beams.　The　full-width　half-maximum　(FWHM)　of　the　far-field　divergent　angle　of　the　Gaussian-like　fundamental　mode　obtained　with　grating　periods　of　23　and　oxide　aperture　diameter　of　8　mu　m　is　less　than　5　degree.　This　opens　a　new　path　for　engineering　a　VCSEL＇s　emission　properties　and　provides　guideline　for　actual　device　fabrication.