Abstract: Objective To evaluate the inhibition method for detection of Lactate Dehydrogenase Isozyme 1 (LDH1) by using Guandine Thiocyante. Methods The imprecision, linearity, recovery test and reference interval of LDH1 were evaluated. Results The imprecision of with-in run of high, mid and low concentration of LDH1 were 4.25%, 1.57% and 0.97%, respectively. The imprecision of between-run of high, mid and low concentration of LDH1 were 4.57%, 2.55% and 1.20%, respectively. The results showed a good linearity (R2=0.998). The average recovery rate was 101.56%. There were no statistical differences between male and female. The reference interval was 33.11±5.76U/L. Conclusion The inhibition method has a good performance in LDH1 detection, and meets the requirements of clinical laboratory, and can be used in clinical application widely.