Transformer is one of the most important components of power system. Preliminarily it looks a simple device but from analysis and innovative point of view it is the big bank of engineering, which comprises civil, mechanical, chemical and electrical engineering. It’s the time of taking challenges and respective solution of minimizing cost of transformer without affecting customer specifications. This is only possible by design optimization process. Optimization is the process of making something better. Problems in engineering, economics and physical and social sciences entail the optimization (minimization or maximization) of an objective function subject to certain constraints (restrictions and tradeoffs). This paper deals with modern design optimization of core type power transformers. Different methods are presented to solve important transformer design problems. Keywords: Transformer design, tranmsformer design optimization(TDO), magnetic circuit, no-load losses, efficiency, sequential quadratic programming (SQP), MATLAB, TDO by iterative method Cite this Article Chirag Parekh, Chetan Kotwal, Hiral Upadhyay. Aspect of Power Transformer Design and Optimization. Trends in Electrical Engineering. 2017; 7(1): 8–18p.