The number of children described as Cornish on school censuses has increased, the local authority has revealed.
In 2011, 41% of pupils were recorded as Cornish compared to 37% in 2010, and 34% in 2009.
The figures are from Cornwall Council's school censuses, which have shown an annual rise since 2007.
Parents, guardians and children in Cornwall have completed the censuses for the council.
In 2011, 28,584 pupils out of 69,811 said they were Cornish compared to 23,808 out of 70,275 in 2009.
Jenefer Lowe, from the Cornish Language Partnership, said: "Our children are more aware of the distinctive place where they live and identify themselves with Cornwall.
Decide their own
"A rise can only be good for Cornwall," she added.
Cornish was added to the school census in 2005 after a campaign by some Cornish language and culture groups for children.
In 2005, 19,988 pupils out of 72,842 described themselves as Cornish, which was 27% of schoolchildren, council figures show.
The Department for Education (DfE) said it recommended parents and guardians should determine the ethnic background for their children at primary schools.
It said pupils at secondary schools could decide their own ethnicity.
Schools are required to complete the annual pupil census by the DfE.