[Objective] To compare the effects of oral versus intravenous tranexamic acid (TXA) on reducing bleeding in unicompart- mental knee arthroplasty (UKA) . [Methods] From June 2020 to June 2021, a total of 61 patients who were undergoing UKA for medial knee osteoarthritis in our hospital were enrolled into this study, and were divided into two groups by random number table method. Of them, 30 patients received oral TXA (the oral group) , while the other 31 patients had TXA intravenously in UKA (intravenous group) . The data re- garding to clinical outcome in perioperative period and blood tests were compared between the two groups. [Results] All the patients had op- erations completed smoothly with no serious complications during operation. There were no significant differences in terms of operative time, total incision length, intraoperative blood loss, postoperative drainage volume, total blood loss, dominant blood loss, hidden blood loss, blood transfusion rate, time to resume walking, incidence of symptomatic thrombosis, incision healing, hospital stay, hospitalization cost and incidence of complications between the two groups (P＞0.05) . The hemoglobin (Hb) was significantly decreased in both groups from 1 to 3 days after surgery (P＜0.05) . Likewise, the hematocrit (Hct) also declined from 1 to 3 days postoperatively, which proved statistically sig- nificant in the in the oral group (P＜0.05) , whereas not statistically significant in the intravenous group (P＞0.05) . There was no statistical significance in HB and Hct between 2 groups at any corresponding time points (P＞0.05) . In terms of ultrasound examination, there was no significant difference in the incidence of intramuscular venous thrombosis postoperatively between 2 groups (P＞0.05) . [Conclusion] Both oral administration and intravenous administration of TAX have similar effects on perioperative blood loss, transfusion rate and incidence of venous thrombosis in UKA.