Microimmunoperoxidase (Micro-IP) test was established for detection of IgM and IgG antibodies of typhus fever. 71 cases with clinically diagnosed typhus fever were examined and the positive rate was 86.3% for paired sera and 60.0% for single sera. The results coincided with those of Micro-IF in all cases, IgM can be detected as early as 4th day after onset and persisted as long as 9 months. 76.2% sera showed positive reaction in the first week post onset. Micro-IP showed group specificity to sera from immunized rabbits and the patients with typhus fever. The advantages of Micro-IP were simple, rapid, sensitive, specific and economic for reagents and time.