The figures for arrests of children aged 17 and under have fallen every year since 2010 and the latest figure continues this trend.
The number of children arrested in Sussex has dropped from 3,220 in 2014 to 2,679 in 2015.
Assistant Chief Constable Laurence Taylor said, "We have seen almost a 50 per cent reduction in the last four years of children being arrested, but we are not complacent and want to improve on this.
"We have been working hard as an organisation to emphasise to officers that all children and young people should be treated as children first. Under our Operation Stepping Stone initiative we are looking at how we, as an organisation, reduce the criminalisation of children and young people. It is vitally important that vulnerability is identified and as far as possible a full understanding of their circumstances is sought before decisions which affect their future are made."
Officers across Sussex have been asked to find alternatives, like community resolution, to avoid arresting young people. The force has voluntary attendance suites in police stations across Sussex where interviews can be conducted without any form of detention. Custody officers are being asked to reinforce this when authorising detention, directing officers to alternatives methods when necessary.
The force is working with partner agencies to ensure a joined up approach for children in care who are a particularly vulnerable group of young people.
Working practices are in place to ensure that we consult with colleagues from youth offending teams and children's services when considering what happens to young people. Intervention by police is not always necessary and often partners can offer better support to help to change the young person's behaviour.
ACC Taylor said, "We work closely with the Police and Crime Commissioner's Youth Commission and consult with them about the policing of children and young people in Sussex. Recent discussion points have been around cybercrime, CSE, healthy relationships and radicalisation. Members also sit on the Youth Independent Advisory Group."
"Our wish is to maintain and enhance the relationship and engagement we have with young people in Sussex. We already have an excellent liaison with local school communities but are looking to develop other ways of working to ensure we keep young people safe and stop them becoming victims or offenders of crime."
Police & Crime Commissioner Katy Bourne said, "I am pleased that Sussex Youth Commission members have been advising the police and giving officers valuable insights into the issues facing young people in our county today. They have been particularly helpful in improving officers' understanding of the relationship between the police and young people. This is exactly what I had in mind when I asked young people from Sussex to take part in this ground-breaking initiative.
"The Sussex Youth Commission enables young people to become part of the solution to tackling crime in their area, rather than being seen as part of the problem."