Purpose　of　Review:　Problematic　internet　use　(PIU)　has　varied　across　countries　and　eras,　but　how　it　may　relate　to　internet　availability　has　not　been　well　examined.　This　cross-temporal　meta-analysis　aimed　to　explore　the　association　between　PIU　severity　changes　and　internet　availability　development　in　China　over　the　past　few　decades　and　how　it　may　relate　to　gender　and　age.　Recent　Findings:　The　results　showed　that　China’s　overall　PIU　level　has　increased　over　time,　and　these　changes　were　associated　with　the　increase　in　factors　related　to　internet　availability.　Gender-related　differences　in　PIU　decreased　over　time,　and　it　appeared　related　to　more　gender　equality　in　internet　penetration　and　use.　In　addition,　college　students　with　relatively　higher　internet　availability　were　found　to　have　higher　overall　PIU　scores　than　secondary-school　students,　and　that　their　PIU　scores　increased　over　time,　while　secondary-school　students’　scores　remained　largely　consistent.　Summary:　PIU　severity　increased　in　China　during　2003–2020,　and　it　appears　to　be　associated　with　the　increase　in　internet　availability,　which　supports　the　internet　availability　hypothesis　on　PIU.　©　The　Author(s),　under　exclusive　licence　to　Springer　Nature　Switzerland　AG　2023.