Police said the female officer was sent to disperse a group of youths breaching lockdown rules at Poulton park in Morecambe on Wednesday, April 1.
One of the teenagers, a girl aged 17, was escorted back home so that further Explanation and Encouragement not to break the rules could be made.
It was during this time that the PCSO was spat at by the girl.
As a result the girl was arrested.
The case has been referred to the Youth Offending Team for an outcome decision.
A spokesperson for Lancashire Police said: "This was a concerning and upsetting incident for the PCSO, who clearly went above and beyond to engage, explain and encourage young people to keep themselves and others safe by abiding by the lock-down rules, only for her to be assaulted."