Two dog attacks took place in Rustington within seven days - near the same park.
The first took place at 8.30am on Sunday, August 17, in Jubilee Avenue recreation ground, where a woman was bitten on her lower leg by an Alsatian.
Then, last Saturday, a man was also bitten on the lower leg near the same recreation ground at about 6.45pm.
Police are trying to trace the dog walker described as a white man in his 50s.
They believe both incidents involved the same man walking two Alsatian dogs on flexi leads.
Anyone with information should contact police by emailing firstname.lastname@example.org or phone 101 quoting serial 1337 of 23/08.