In order to study the relationship between serum C-reactive protein (CRP) levels, leuko-cyte count and carotid plaque in patients with ischemic stroke, carotid duplex examination was per-formed by high-definition imaging (HDI) 5000 triplex system. Serum CRP was measured by nephe-lometry within 72 h after index ischemic stroke. A lesion was considered a plaque in the presence ofa maximum intimal-medial wall thickness (IMT) 1.2 mm. Results of carotid ultrasonography weredivided into two groups: M1, normal (IMT ＜l. 2 mm) and M2, abnormal (IMT ≥1.2 mm). Theresults showed that the mean age of M2 was significantly older than that of M1 (69.7± 10.4 versus62.5±9.6, P=0. 001). The patients with hypertension and diabetes mellitus (78 %, 35 % re-spectively)in M2 were significantly more than those (52 %, 18 % respectively) in M1 (P＜0.0l,P＜0.05). There were 32 (65 % ) patients with elevated CRP levels in M2, but 33 (46 %) pa-tients with elevated CRP levels in M1, with the difference being significant between the two groups(P＜0.05). The levels of serum glucose and leukocyte count (8. 1±5.5, 10.3±4.0, respectively)in abnormal CRP group were significantly higher than that of normal CRP group (6.4 ± 2.8, 8.7 ±3.4) (P＜0.05, P＜0.05); elevated CRP levels was found in 42 (62 %) patients with territory in-farction and 23 (43 %) patients with lacunar infarction respectively, with the difference being sig-nificant between these two groups (P＜0.05). It was concluded that the elevation of CRP levelswas an significant clinical index for carotid plaque in patients with acute cerebral infarction.