On April 3,2024,a magnitude 7.3 earthquake occurred in the Hualien Sea area,Eastern Taiwan,China,according to the China Earthquake Networks Center. The earthquake took place along the suture zone where the Eurasian Plate converges with the Philippine Sea Plate. Studying the source parameters of this earthquake sequence provides valuable insights into the seismic characteristics of the Zonggu fault in the Hualien region,Taiwan. Using broadband digital seismic data,we determined the focal mechanism solutions,seismic radiation energy,event duration,and Coulomb stress for the entire seismic sequence. The results are as follows: ① The main earthquake,located near the coast of Hualien,is a thrust-type event,and the four aftershocks with M_S≥6.0 are also thrust-type,consistent with the tectonic properties of the main fault zone in the focal region. ② The radiation energy analysis reveals that the main shock is a high-energy event,while the aftershocks release energy less efficiently than the main event. ③ The Coulomb stress distribution shows that the main earthquake caused significant stress unloading in the area near the epicenter projection,with the stress redistribution aligning closely with the observed dislocation concentration.