The present study was performed to identify the relationship between plasminogen activator (PA) and Heat Shock Protein-90 (HSP-90) in porcine uterus tissues during the estrous cycle. Porcine uterus tissues were obtained from preovulatory (Pre-Ov), post-ovulatory (Post-Ov) and early to mid-luteal (Early-mid L) stages. The protein was extracted from uterus tissue by using M-PER Mammalian Protein Extraction Reagent. Proteins were refined by RIPA Buffer and quantified by BCA methods. As results, t-PA expression was significantly (p<0.05) higher from pre-ovulatory(Epithelium tissue: $29,067{mu}g/{mu}l$, Myometrium tissue: $30,797{mu}g/{mu}l$) compared to the post-ovulatory stage(Epithelium tissue: $54,357{mu}g/{mu}l$, Myometrium tissue: $53,270{mu}g/{mu}l$) and early to mid-luteal stage(Epithelium tissue: $42,380{mu}g/{mu}l$, Myometrium tissue: $43,139{mu}g/{mu}l$). On the other hand, the uPA expression indicated higher from early to mid-luteal stage (Epithelium tissue: $0.02198{mu}g/{mu}l$, Myometrium tissue: $0.02412{mu}g/{mu}l$) than pre-ovulatory stage (Epithelium tissue: $0.01577{mu}g/{mu}l$, Myometrium tissue: $0.01531{mu}g/{mu}l$) and post-ovulatory stage(Epithelium tissue: $0.01414{mu}g/{mu}l$, Myometrium tissue: $0.01429{mu}g/{mu}l$). However, expression of u-PA did not differ from each estrous cycle in the epithelium tissue and myometrium tissue(p<0.05). Expression of HSP-90 was differ t-PA and u-PA from pre-ovulatory in Epithelium tissue($25,423{mu}g/{mu}l$) and early to mid-luteal stage in epithelium tissue($177,922{mu}g/{mu}l$) and myometrium tissue($26,664{mu}g/{mu}l$). These results suggest that HSP-90 and u-PA were related with change of uterus cycle according to the reformation of the tissues in porcine uterus.