Police executed a search warrant at an Old Orchard Road home Tuesday morning and took a computer, floppy discs, and photographs.
OPP Detective Inspector Bob Matthews said approximately 500 graphic files were found on the computer.
Matthews said the images show pre-pubescent children engaged in explicit sexual activity with adults and other pre-pubescent children.
Project P conducted a two-month investigation after receiving information from a detective in the Crimes Against Children Unit of the San Bernardino Sheriff's Department in California.
OPP Detectice Sergeant Frank Goldsmith said the investigation was not part of an international child pornography ring using the Internet.
Goldsmith said material was probably sent to California and intercepted by the officers in San Bernardino, who alerted police in Ontario.
Timothy Stephen Lamming, 23, of Old Orchard Road, is charged with two counts of possession of child pornography, one count of distribution of child pornography, and once count of distribution of obscene material.