A quantum spin liquid (QSL) is a new state of matter in which spins show no magnetic order down to zero temperature but are highly entangled. Elucidating the magnetic interactions of a QSL is essential to understanding the microscopic mechanism underlying this exotic state. Recently, our neutron scattering experiments on a quantum spin liquid (QSL) candidate YbMgGaO4 have revealed clear spinon excitation at zero temperature limit (70 mK), which is a hallmark of a QSL state. Hamiltonian combining XXZ model and spin-orbital coupling induced anisotropic interactions has been proposed to explain the stabilization of QSL state in this compound. Here, we propose to measure YbMgGaO4 single crystals with in-plane magnetic field to probe and determine the anisotropic interactions to help understand the origin of QSL state in triangular lattice.