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 μg/μl, Myometrium tissue: 30,797 μg/μl) compared to the post-ovulatory stage(Epithelium tissue: 54,357 μg/μl, Myometrium tissue: 53,270 μg/μl) and early to mid-luteal stage(Epithelium tissue: 42,380 μg/μl, Myometrium tissue: 43,139 μg/μl). On the other hand, the uPA expression indicated higher from early to mid-luteal stage (Epithelium tissue: 0.02198 μg/μl, Myometrium tissue: 0.02412 μg/μl) than pre-ovulatory stage (Epithelium tissue: 0.01577 μg/μl, Myometrium tissue: 0.01531 μg/μl) and post-ovulatory stage(Epithelium tissue: 0.01414 μg/μl, Myometrium tissue: 0.01429 μg/μl). 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 μg/μl) and early to mid-luteal stage in epithelium tissue(177,922 μg/μl) and myometrium tissue(26,664 μg/μl). 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.