The research focuses on the impact evaluation of agriculture and non-agriculture national and international trade, and economic policy reforms in economic development and welfare of Bangladesh. This research especially evaluates the agro-industrialization impact on the economy and welfare of Bangladesh. For impact assessment, this study simulates a set of 10 scenarios by the single country CGE model (Lofgren et al. 2002) and a set of 5 scenarios by the multi-regional, multi-market comparative static GTAP model (Hertel, 1997). Assessment of policy reform through the single country CGE model reveals that the overall impact of trade liberalization is mixed among the sectors and households of the economy. The mixed impact keeps the debate of trade liberalization alive in case of Bangladesh. Non-agriculture trade liberalization contributes more in economy and welfare compare to agriculture trade liberalization. Agri-industry sector trade liberalization with ensuring increase productivity can ensure substantial increase in production and export of agribusiness sectors. As alternative to trade policy options, increase productivity with increase wage of agri-industry sector can increase production and welfare of country. World food price rise problem can be managed through reduction of food import tariff, which can I like to extend my appreciation to my friends Md Ismail Hossain, Mst. Esmat Ara Begum, A. K. M. Akhtaruzzaman Bosunia and Md. Saykhul Arifin for there valuable support in my study life.My enormous debt of gratitude also goes to Ishrak Karim, Ishtiaque Karim Robin, Rashida Khatun, Khadiza Parveen, Samsunnahar Lovely, Mizanur Rahman and Altaf Hossain for their deep most love, care, and respect that I have got during this study period.On a personal note I would like to deeply to my father Dr. Abu Enamdar Hossain, my mother Mrs Mahafuza Hossain, my brother in law Lt. Col. Lutful Hassan Rumi, my sister Ekrama Dil Afroze and my nephews for their unconditional love and support. I would like to lastly but with the greatest appreciation of above all to the Almighty Allah for his immeasurable grace, profound kindness, and bestowing mercy from the start to end of the completion of this research work.