Aim To investigate the characteristics of microembolic signal of cerebral infarction in young adults.Methods A total of 111 consecutive young adult patients with cerebral infarction, 73 cases in the control group for the same period in healthy subjects were included in the study. All were treated with microembolic signal, regulatory T cell, apolipoprotein A1 and lipoprotein-associated phospholipase A2 detection. Results The positive rate of microembolic signal, apolipoprotein A1 and lipoprotein-associated phospholipase A2 levels of young adult patients group were higher than the control group (28/111 vs 0/73, P＜0.05;34.57%±2.12% vs 27.38%±1.51%, P＜0.05; 255.85±10.77 μg/L vs 137.22±8.97 μg/L,P＜0.05); The level of regulatory T cell was lower than the control group(8.98%±1.27% vs 10.27%±1.25%,P＜0.05). The positive rate of microembolic signal, apolipoprotein A1 and lipoprotein-associated phospholipase A2 levels of the unstable plaque group were higher than the non unstable plaque group(15/19 vs 13/92, P＜0.05; 36.57%±2.32% vs 34.16%±1.12%, P＜0.05;311.33±10.77 μg/L vs 244.39±9.67 μg/L,P＜0.05) . The level of regulatory T cell was lower than the non unstable plaque group (7.45%±1.87% vs 9.30%±2.71%, P＜0.05). The positive rate of microembolic signal and lipoprotein-associated phospholipase A2 level of severe stenosis group were higher than that in non severe stenosis group(7/9 vs 21/102, P＜0.05; 295.23±11.37 μg/L vs 252.38±10.07 μg/L, P＜0.05). The level of apolipoprotein A1 and lipoprotein-associated phospholipase A2 of microembolic signal positive group were higher than negative group(36.97%±2.72% vs 33.76%±1.12%, P＜0.05; 308.21±9.57 μg/L vs 238.19±8.92 μg/L, P＜0.05); The level of regulatory T cell was lower than negative group (7.49%±1.77% vs 9.48%±2.71%, P＜0.05). Conclusion There were not normal microembolic signal and immune indexes in youth patients with acute cerebral infarction.