A study of 74 schools from the National Foundation for Educational Research found that fewer youngsters now believe that reading is difficult, compared with 10 years ago.
However, there is a substantial decrease in pupils reading for pleasure.
The researchers say the national literacy strategy may be to blame.
Sixty-five per cent of nine-year-olds and 73 per cent of 11-year-olds said they did not think reading was difficult, compared with 56 per cent and 62 per cent respectively in 1998.
Just over seven out of 10 of the younger age group enjoy reading as a pastime, compared with 78 per cent five years ago, while for 11-year-olds, the proportion has declined from 77 per cent to 65 per cent.
Children said they preferred watching television to going to the library or reading.
But the biggest changes in attitudes were among boys. In Year 6, only 55 per cent of boys said they enjoyed stories compared with 70 per cent in 1998. Among girls there was a 10-point decline, from 85 to 75 per cent.
Marian Sainsbury, NFER principal researcher, who conducted both surveys, said: "The children who were surveyed in 2003 were the first to have received five years of teaching according to the national literacy strategy.
"The 1998 survey was carried out the term before the strategy was introduced nationally."
She said that other studies and official statistics had shown that standards of reading were rising, and that this was probably a direct reflection of the strategy.
But she added: "On the other hand, enjoyment levels have declined. We have no direct evidence from this survey of the reasons for the change, but it is possible this is also related to the drive to improve standards.
"Children are learning skills and reading material that has usually been chosen by the teacher rather themselves. There may have been less emphasis on the sheer pleasure to be gained from books."
Dr Sainsbury said similar surveys would be carried out every two years to monitor attitudes to reading among pupils.
A separate study released by the Schools Health Education Unit in Exeter, in October, found that the proportion of 10-year-old boys who read books at home nearly halved during the first five years of the national literacy strategy.
The report said that the percentage of Year 6 boys who read during dinner-time, play-time, or in the evening has dropped from 29 per cent in 1997 to 17 per cent in 2002.
matt buck 31 Children's Attitudes to Reading: www.nfer.ac.uk