The staff were arrested after pictures emerged of residents at the Barnsley care home, the name of which has not been disclosed to avoid identifying vulnerable people, which police said were "inappropriate and unprofessional".
South Yorkshire Police said today (Friday) that while the pictures did indeed show a lack of professional integrity, there was no evidence to show criminality.
The carers involved currently remain suspended and under investigation by the council and Care Quality Commission (CQC).
A force spokeswoman said: "Although the photos are both inappropriate and unprofessional, extensive enquiries conducted by our officers found that there is not sufficient evidence to support a criminal prosecution.
"All families involved have continually been kept updated and have now been informed of the outcome.
"As the criminal investigation will now be closed, no further police action will be taken against the seven carers arrested.
"However, the carers remain suspended from work, and the matter will continue to be investigated by the care provider, Barnsley Council and the Independent Care Home Inspectors CQC."