In the last two years, there have been more than 380 reported incidents of child grooming using social media in the Thames Valley, according to children's charity, the NSPCC.
Officials say 274 offences were recorded in the year to April 2019 compared with 114 in the previous year.
They say the number of children targeted on Instagram has risen.
The NSPCC said across the UK, police recorded 4,373 offences of sexual communication with a child in the year to April 2019, compared with 3,217 the previous year.
Two years ago the law changed to make sending explicit messages to young people on the networks a crime.
In the year to April 2019, 34% of cases in the UK involved Instagram compared to a fifth of cases the previous year, the charity said.
Thames Valley Police said: "We have seen a growing number of cases where children and young people have been targeted through popular apps and social media platforms but we know many incidents still go unreported.
"It is our priority to engage with the public to make sure children and young people are aware of the dangers of online grooming.
"Keeping children safe from harm is all of our responsibility, we rely on information from members of the public to identify crimes and keep victims safe.
"We are committed to tackling this issue and bring offenders to justice.
"If you come across a child you believe could be a victim of online abuse contact the police on 101. Always call 999 if you believe they are at immediate risk from harm. Alternatively you can contact the NSPCC helpline on 0808 800 5000."