Objective To explore the possible negative interference of circulating cardiac troponin Ⅰ(cTnI) autoantibody on the immunoassay of cTnI in five commonly used cTnI detection systems. Methods Thirteen patients with positive cTnI autoantibodies in their serum samples were firstly screened and selected from 121acute myocardial infarction (AMI) patients using ELISA assay. The serum cTnI values and their recovery rates were then carefully measured and analyzed. Results cTnI values in these 13 samples showed amazing difference in the five detection systems, demonstrating various degrees of pseudo-drop, or even false-negative. One sample with low recovery was detected in Access-2 system. One sample with low recovery as well as one sample with moderate recovery were detected in Architect i2000 (Abbott). Two samples with moderate recovery and one sample with low recovery were detected in Axsym(Abbott). Three samples with moderate recovery and two samples with low recovery were detected in Dimension X Pand (Dade Behring)and one sample with moderate recovery together with four samples with low recovery were detected in Vidas (Biomerieux). And the serum levels of autoantibodies (A450) positively correlated with the degrees of their negative interference for the detection of cTnI. The R2 and P values on each system were 0. 841 (P <0. 01)vs Access-2, 0. 808 (P < 0. 01) vs Architect i2000 (Abbott), 0. 772 (P < 0. 01) vs Axsym (Abbott), 0. 707 (P < 0. 01) vs Dimension X Pand (Dade Behring) and 0. 424 (P < 0. 05) vs Vidas (Biomerieux), respectively. Conclusion Circulating autoantibodies of cTnI can induce considerable negative interference in all the 5 commonly used cTnI detection systems, which might then lead to incorrect judgments of the obtained results of cTnI in daily clinical work.