Parents have been warned to keep a close eye on the comics young children read as a survey found 27 per cent of primary school pupils spent an average of two hours a day reading them.
The Hong Kong Education Policy Concern Group, which conducted the survey, warned many comics contained violence and sex.
In the survey of almost 10,000 pupils, 88 per cent said they enjoyed reading comics and 29 per cent said they read between three and six every week. More than 30 per cent said they spent between $31 and $100 a week buying comics.
Twenty-six per cent said they preferred comics with a sense of justice, while 10 per cent said they liked comics featuring violence and sex.
Japanese comic series characters Super Black Kitty, Card Captor Sakura and Pokemon were the three favourites.
A total of 35 per cent of respondents from lower-income families bought comics while only 17 per cent from upper-middle class families did so.
The group's chairman, Mervyn Cheung Man-ping, warned most popular comics carried violence, gang fighting and indecent content.