Multiple-port directional emission microlasers are potential light sources and optical signal processing units in photonic integrated circuits. Connecting bus waveguides to a microresonator is a simple method to realize directional emission microlasers. In this paper, we investigate square and circular resonator microlasers connected with multiple bus waveguides. The mode characteristics of the microresonators connected with multiple bus waveguides are simulated by finite-difference time-domain technique, and the numerical results of mode Q factors and output coupling efficiencies show that high efficiency directional emission microresonator lasers can be realized. Furthermore, the microcylinder laser connected with a bus waveguide fabricated by planar technology processes is reported, and the lasing spectra of square microlasers with four vertices connected to bus waveguides are analyzed.?2011 SPIE.