<Ul> <Li> First round: 12 teams (ranked 35--46) played home - and - away over two legs . The six winners advanced to the second round . </Li> <Li> Second round: 40 teams (ranked 1--34 and six first round winners) were divided into eight groups of five teams to play home - and - away round - robin matches . The eight group winners and the four best group runners - up advanced to the third round of FIFA World Cup qualification as well as qualifying for the 2019 AFC Asian Cup finals . </Li> <Li> Third round: The 12 teams (an increase from 10 for 2014) which had advanced from the second round were divided into two groups of six teams to play home - and - away round - robin matches . The top two teams of each group qualified for the 2018 FIFA World Cup, and the two third - placed teams advanced to the fourth round . </Li> <Li> Fourth round: The two third - placed teams of each group from the third round played home - and - away over two legs . The winners advanced to the inter-confederation play - offs . </Li> </Ul> <Li> First round: 12 teams (ranked 35--46) played home - and - away over two legs . The six winners advanced to the second round . </Li> <Li> Second round: 40 teams (ranked 1--34 and six first round winners) were divided into eight groups of five teams to play home - and - away round - robin matches . The eight group winners and the four best group runners - up advanced to the third round of FIFA World Cup qualification as well as qualifying for the 2019 AFC Asian Cup finals . </Li> <Li> Third round: The 12 teams (an increase from 10 for 2014) which had advanced from the second round were divided into two groups of six teams to play home - and - away round - robin matches . The top two teams of each group qualified for the 2018 FIFA World Cup, and the two third - placed teams advanced to the fourth round . </Li>

How many teams from asia qualified for participation in fifa world cup 2018