Shanghai was ranked first in mathematics, science and reading in a report on global education released every three years.

Sixty-five countries and regions took part in the tests for the Paris-based Organization for Economic Cooperation and Development. Its PISA report (Program for International Student Assessment) is the single largest study of global schooling.

The study is highly influential, with participating countries and regions representing more than 80 percent of the global economy and often adapting policy in response to the findings.

The first PISA survey was carried out in 2000, with Shanghai joining the rankings in 2009 and coming first in the same three categories that year as well as first overall.

Around 6,400 students from 155 schools in Shanghai took part in the latest assessment in April last year. Globally, around half a million 15-year-olds took part. The tests are based on a 1,000-point scale.

Zhang Minxuan, leader of the Shanghai PISA program and President of Shanghai Normal University, attributed Shanghai's students' performance in mathematics to more chances to learn the subject, ability and family backgrounds.

Shanghai students also reported an average of 13.8 hours every week doing school assignments, the highest and almost three times the average 4.9 hours.