Biofilms　are　central　to　some　of　the　most　urgent　global　challenges　across　diverse　fields　of　application,　from　medicine　to　industries　to　the　environment,　and　exert　considerable　economic　and　social　impact.　A　fundamental　assumption　in　anti-biofilms　has　been　that　the　coating　on　a　substrate　surface　is　solid.　The　invention　of　slippery　liquid-infused　porous　surfaces-a　continuously　wet　lubricating　coating　retained　on　a　solid　surface　by　capillary　forces-has　led　to　this　being　challenged.　However,　in　situations　where　flow　occurs,　shear　stress　may　deplete　the　lubricant　and　affect　the　anti-biofilm　performance.　Here,　we　report　on　the　use　of　slippery　omniphobic　covalently　attached　liquid　(SOCAL)　surfaces,　which　provide　a　surface　coating　with　short　(ca.　4　nm)　non-cross-linked　polydimethylsiloxane　(PDMS)　chains　retaining　liquid-surface　properties,　as　an　antibiofilm　strategy　stable　under　shear　stress　from　flow.　This　surface　reduced　biofilm　formation　of　the　key　biofilm-forming　pathogens　Staphylococcus　epidermidis　and　Pseudomonas　aeruginosa　by　three-four　orders　of　magnitude　compared　to　the　widely　used　medical　implant　material　PDMS　after　7　days　under　static　and　dynamic　culture　conditions.　Throughout　the　entire　dynamic　culture　period　of　P.　aeruginosa,　SOCAL　significantly　outperformed　a　typical　antibiofilm　slippery　surface　[i.e.,　swollen　PDMS　in　silicone　oil　(S-PDMS)].　We　have　revealed　that　significant　oil　loss　occurred　after　2-7　day　flow　for　S-PDMS,　which　correlated　to　increased　contact　angle　hysteresis　(CAH),　indicating　a　degradation　of　the　slippery　surface　properties,　and　biofilm　formation,　while　SOCAL　has　stable　CAH　and　sustainable　antibiofilm　performance　after　7　day　flow.　The　significance　of　this　correlation　is　to　provide　a　useful　easy-to-measure　physical　parameter　as　an　indicator　for　long-term　antibiofilm　performance.　This　biofilm-resistant　liquid-like　solid　surface　offers　a　new　antibiofilm　strategy　for　applications　in　medical　devices　and　other　areas　where　biofilm　development　is　problematic.