Aiming at the monitoring and regulating of three-phase unbalance in low-voltage (LV) grid, the causes of three-phase unbalance phenomenon and its influence on line loss are analyzed. Then, the shortcomings of two common practices in monitoring are analyzed, that is, focusing on the three-phase unbalance degree of the secondary winding of LV transformersand the unbalance degree of electric energy instead of real time power. After that, the limitations of the widely-used three-phase centralized unbalance compensation equipment are analyzed and verified by the impedance analysis of typical distribution transformer and distribution line. Finally, regarding the above-mentioned problems, the specific suggestions are proposed, which providesa reference for power grid enterprises and distribution network operators in monitoring and regulating of three-phase balanced in LV grid.