Objective To investigate the status of uncertainty in illness and social support among patients with post-traumatic brain syndrome (PTBS) and analyze their correlation.Methods One hundred and fourteen patients with PTBS were selected by convenience sampling and assessment.They were evaluated by Chinese disease Mishel Uncertainty in Illness Scale (MUIS) and Social Support Assessment Scale (SSAS) and the correlation of two scales was analyzed.Results MUIS total score was(135.23±19.29) scores with a median of 128.74 scores and SSAS total score was (43.14±5.54) scores with a median of 42.00 scores in patients with PTBS.Among 114 patients with PTBS,regarding ambiguity score was negatively correlated with objective support,subjective support,utilization degree of support and SSAS total score,r=-0.301,-0.374,-0.521,-0.509,complexity score was negatively correlated with objective support,sub-jective support,SSAS total score and utilization degree of support,r=-0.367,-0.326,-0.355,-0.533,both lack of information and regarding unpredictability score were negatively correlated with utilization degree of support,r=-0.376,-0.330,MUIS total score was negatively correlated with objective support,utilization degree of support and SSAS total score,r=-0.284,-0.424,-0.305.Conclusion There is high uncertainty of PTBS patients;increase of patients' social support will be good for decreasing the ambiguity and com-plexity among patients' uncertainty;promotion of patients' utilization degree of support will help to reduce patients' lack of information and unpredictability.