Objective To discuss the diagnostic value of THMMDI in examining mycoplasma in patients of urogenital tract infection in vivo. Method THMMDI, culture and PCR were performed in 105 patients with urogenital tract infection. Result There is no significant difference in positive rate of mycoplasma by THMMDI , culture and PCR(P0.05). Conclusion It is a rapid and simple method to examine mycoplasma in patients of urogenital tract infection by THMMDI.