Grand Ayatollah Abdul-Karim Haeri Yazdi (may his soul rest in peace) was a comprehensive figure who provided abundant assistance to the Islamic world. He is named as the reviver of Qom Seminary. This research examines the constructive role of Grand Ayatollah Haeri in the revival and development of preaching in the recent century, aiming to demonstrate his valuable services in the revival of preaching both quantitatively in the scope of preaching and qualitatively in the content of preaching. The present study, using descriptive-analytical method and library research, addresses the question of what role Grand Ayatollah Haeri played in the revival and expansion of preaching in the recent century of Qom Seminary. The current paper has elucidated the constructive role of Grand Ayatollah Haeri in two steps: the first step illustrates his valuable services in the revival of preaching quantitatively and in the scope of preaching, including actions such as establishing Qom Seminary, dispatching preachers to cities and towns, teaching foreign languages to students, and honoring the best propagators. The second step examines his constructive services in the qualitative aspect and content of preaching, including actions such as reviving the tradition of permission in preaching, combating pseudo-methods, preserving Islamic unity, and efforts in removing distortions from mourning ceremonies.