In　this　paper,　an　adjustable　flexible　antenna　is　designed　and　implemented.　The　antenna　is　based　on　liquid　metal　and　embedded　in　a　polydimethysiloxane　(PDMS)　substrate.　On　the　premise　of　no　additional　circuit　elements,　the　frequency　can　be　continuously　adjusted　by　using　the　surface　tension　of　liquid　metal　and　the　reasonable　design　of　complementary　split　ring　resonator　(CSRR)　topology　on　antenna　patch.　The　frequency　range　of　this　adjustable　antenna　covers　2.6　GHz　to　4.2　GHz.　The　corresponding　CSRR　size　for　each　frequency　band　is　determined　by　simulation　design　and　experimental　verification.　This　design　is　especially　suitable　for　areas　requiring　safe,　conformal　and　tunable　antennas,　such　as　medical,　military　and　wearable　equipment.　©　2019　IEEE.