A wetness notification system includes a detecting unit (2), a clip unit (3), a receiver unit (4), and a sampling unit (5). The detecting unit (2) includes a sleeve body (21), amounting seat (29), a moisture detector (22), a casing (23), a processor (24), a wireless transmitter (25), and a battery (26). The sampling unit (5) includes a substrate (51) and at least one sampling element (52). The substrate (51) is made of flexible material and removably attached to the mounting seat (29). The sampling element (52) is disposed on the substrate (51) for contacting and sampling the urine within the clothing article (7) for urinalysis.