The combinations of furosemide and 70% ethanolic extract of kumis kucing leaves cause pharmacology and pharmacokinetic interactions that can alter levels in plasma and diuretic effect of furosemide itself. This study aimed to observed the effect of 70% ethanolic extract of kumis kucing leaves on diuretic effect and pharmacokinetic parameters of furosemide in white male rats. Thirty Sprague Dawley male rats divided into five group of six animals each and administrative orally for 4 days which are control group was given 1% CMC, furosemide group was given 7,2 mg/200g bw suspension of furosemide, extract was given 700 mg/kg bw suspension of 70% ethanolic extract of kumis kucing leaves, 1^st combination group was given 700 mg/kg bw extract suspension for 4 days followed by suspension of furosemide 7,2 mg/200 g bw, and 2^nd combination group was given 350 mg/kg bw extract suspension for 4 days followed by suspension of furosemide 7,2 mg/200 g bw. On the 4^th day of treatment performed blood sampling and analyzed the levels of furosemide in plasma using HPLC. Urine volume is measured in the fourth day, blood pressure is measured before treatment and on the fourth day using non-invasive blood pressure measurement, and sodium and potassium level are measured on 24 hour urine using AAS. The results showed 70% ethanolic extract of kumis kucing leaves improve diuretic effect of furosemide on urine volume, sodium level, and systole blood pressure and improve pharmacokinetic parameters of furosemide on Cp_maks, and Area Under the Curve (AUC) (P < 0,05).