TEHRAN, Young Journalists Club (YJC) - Over 900 Iranian and foreign companies are taking part in the event.
The participants are presenting their accomplishments and achievements in the expo.
89 foreign companies from Turkey, China, Poland and the Netherlands are among the participants.
Norway, Czech, Italy, Germany, Brazil, South Korea, India, Finland, France, Britain, Hong Kong, Switzerland, Australia, Austria, Japan and Spain have attended the expo indirectly.
Industrialization, retrofitting, modernization of mass production, renovation of worn-out texture, installations and construction facades and steel constructions are some aspects of the expo.