With the Z-scan and Island-scan two schemes and selective laser melting (SLM) technology, Ti6Al4V specimens with different overhang angles are fabricated, and the relationships among molten pool behavior, overhang angle and forming quality are studied. The results show that, in the forming process, the molten pool area first increases sharply till arrives at a peak value, and then decreases slowly with the increment of fabrication height. Compared with that for the plane-scan scheme, the molten pool for the contour-scan scheme is more obviously instable and its area has a larger amplitude. With the decrement of overhang angle, the molten pool area becomes small and the overhang surface becomes rough. Compared with that for the Z-scan scheme, the molten pool area for the Island-scan scheme is smaller, the molten pool is more instable, and the overhang surface roughness is higher.