Objective To explore the distribution of nanobacteria in prostatic calculus and investigate its role in the formation of prostatic calculus.    Methods The stones of 40 patients with prostatic calculus was used to isolate and culture the possible bacteria.  The genomes of obtained bacteria were extracted

and the 16S rRNA was amplified by PCR followed by sequencing.   Results The obtained specific fragment had a 98% resemblance with 16S rRNA of nanobacteria: Score=2 480 bits (1 290)

Expect=0.0; Identities=1 387/1 409 (98%)

Gaps=4/1 409 (0%); Strand=Plus/Plus.   Conclusion Nanobacteria is proved existing in the stones of prostatic calculus patients by PCR and sequencing.