YAP-TEAD　complex　plays　an　important　role　in　tumorigenesis.　5-HT　is　proved　to　upregulate　YAP　expression　by　our　previous　study　and　VGLL4　is　found　to　compete　with　YAP　for　binding　to　TEAD　in　several　of　cancers.　Here,　we　investigated　whether　5-HT　could　affect　progression　and　prognosis　of　hepatocellular　carcinoma　(HCC)　patients　and　regulate　YAP/VGLL4　balance.　We　found　that　5-HT　and　YAP/VGLL4　ratio　were　higher　in　HCC　patients　and　closely　related　with　progression　and　poor　prognosis.　Furthermore,　5-HT　level,　YAP/VGLL4　ratio　and　tumor　size　were　proved　as　independent　risk　factors　of　HCC　patients　in　our　study.　Based　on　the　independent　risk　factors,　nomogram　was　established　to　exactly　predict　prognosis　of　HCC　patients.　Additionally,　the　study　revealed　that　a　higher　total　point　of　the　nomogram　was　closely　correlated　with　poorer　prognosis.　As　a　result,　5-HT　might　contribute　to　the　progression　and　poor　prognosis　of　hepatocellular　carcinoma　via　regulating　YAP/VGLL4　balance.　Therefore,　the　established　nomogram　based　on　the　independent　risk　factors　may　become　an　important　part　of　HCC　prediction　system　and　YAP/VGLL4　balance　may　be　a　potential　therapeutic　target　in　future.