Joined as lecturer in Department of Islamic History & Culture, University of Dhaka (1990); Professor (2004);Vice Chancellor(September 06, 2017-); Pro-Vice Chancellor (June 2016 – September 05, 2017  );  Dean, Faculty of Arts (2014-2016); Provost, Kabi Jasimuddin Hall (2007-2013); Chairman, Department of Islamic History & Culture (2008-2011); Chairman, Department of Arabic (2015-2016); General Secretary (2004, 2005 & 2006) and Vice President (2009, 2011) of the Dhaka University Teachers’ Association; Elected member for different period in the Dhaka University Senate, Syndicate & Academic Council; Nominated member in several public and private University Senate, Syndicate & Academic Council for different tenure; Convenor, Textbook Crisis Resolution National  Committee (2008), Convenor, Textbook Printing and Distribution Oversee and Advisory Committee (2009 & 2010); Member, Prime Minister’s Education Assistance Trust (2012 – ); Member, National Education Policy 2010 Implementation Committee; Member, National Curriculum Coordination Committee (NCCC); Editorial Member, Journal of Serajul Haque Centre for Islamic Research and the  Journal of the Asiatic Society of Bangladesh (Humanities); Editor,  Bangladesh Itihas Parishad Journal Itihas (2009-2014); Council Member (2006-2009), Asiatic Society of Bangladesh; General Secretary (2005-2009) and Vice President (2016- ) , Bangladesh Itihas Parishad; General Secretary, Aligarh Old Boys’ Association of Bangladesh (2007-2009); Editor, Islam and Moral Learning (textbook for classes VI-X); Moderator, Introduction to Bangladesh and the World (text book for Classes ix–x); President, Bangladesh College-University Teachers’ Association (2014- ); Presidium-member, Bangladesh Peshajibi Somonnoy Parishad (2013- ); Presidium-member, Bangladesh-Russia Moitry Samity (2017- ). Besides, associated with different professional and socio-cultural bodies like Bangla Academy, Bangladesh Association for American Studies, Bangladesh Association for Fulbright Scholars, Indian History Congress and so on.