More than 950 Senior Four candidates from Yei River County started the Uganda National Examination Board or UNEB on Monday.
Speaking at Yei Girls launching centre, primary schools inspector Martin Woja Balla disclosed the number of students sitting for the Ugandan exams, Easter Radio reported.
He was also representing the county education department.
South Sudan National Examinations Council secretary in the national Ministry of Education, Science and Technology, Madding Manyok Ajak, said South Sudan will implement its own curriculum to stop foreign examinations by 2014.
There are 11 UNEB centres in Yei, including Yei Day, Yei Girls, Saint Joseph and Nile High secondary schools.
The examination began with Geography one and two and concludes with Fine Art five on November 12, 2013.