We　present　an　experiment　of　observing　the　geometric　phase　in　a　superconducting　circuit　where　the　resonator　and　the　qutrit　energy　levels　are　dispersively　coupled.　The　drive　applied　to　the　resonator　displaces　its　state　components　associated　with　the　qutrit＇s　ground　state　and　first-excited　state　along　different　circular　trajectories　in　phase　space.　We　identify　the　resonator＇s　phase-space　trajectories　by　Wigner　tomography　using　an　ancilla　qubit,　following　which　we　observe　the　difference　between　the　geometric　phases　associated　with　these　trajectories　using　Ramsey　interferometry.　This　geometric　phase　is　further　used　to　construct　the　single-qubit　π-phase　gate　with　a　process　fidelity　of　0.851±0.001.　©　2018　Chinese　Physical　Society　and　IOP　Publishing　Ltd.