Enhancing urban trails design quality can encourage people to use them. This study compared two urban trails with different functions in Tehran. Trying to discover that while walking on the urban trails which parts of the path has the most effects on the cognitive functions of users. The aim is to enhance the urban trails quality by understanding human’s reaction. We use electroencephalography device as a cognitive science tool. Results illustrate that first three minutes of strolling has the most cognitive effects on users. We suggest improving the space quality of urban trails after the first minutes of entrancing. Keywords: urban trails; EEG; park; commercial walkway 2514-751X © 2017 The Authors. Published for AMER ABRA by e-International Publishing House, Ltd., UK.. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer–review under responsibility of AMER (Association of Malaysian Environment-Behaviour Researchers), ABRA (Association of Behavioural Researchers on Asians) and cE-Bs (Centre for Environment-Behaviour Studies), Faculty of Architecture, Planning & Surveying, Universiti Teknologi MARA, Malaysia.