Objective: The objective of this study is to determine the validity of analytical methods in OFX antibiotic study in human urine (in vitro) using an SPE-HPLC/UV. In this study, SPE was applied in preparing the analysis of ofloxacin using HPLC embedded UV detector. Methods: C-18 (octadecylsilane) cartridge (100 mg, particle size 10 ?m) of SPE was employed in preparing a sample to determine further of analytes using HPLC with phosphate buffer 0.025 M (pH 2.5) and acetonitrile (85.5:14.5) as mobile phase and a flow rate of 1.2 m l/min. UV detector was adjusted at 295 nm with the internal standard ciprofloxacin. Results: The calibration curves for the ofloxacin were linear over concentrations ranging from 1.15 to 36.0 ?g/ml with a correlation coefficient (r) from 0.9998 to 0.9999. The coefficients of variation obtained from ofloxacin were less than 10 %. Ofloxacin on the area ratio of peak height and a segment of the chromatogram, LOD and LOQ of ofloxacin were 0.12 and 0.4 ?g/ml, respectively. The recovery of ofloxacin from spiked human urine was 96.0 %. Conclusion: The validation methods that including parameters: selectivity, repeatability, linearity, detection limit, quantification limit, precision, accuracy, and suitability of the system. The methods used have validity according to the requirements that might be used to analyze ofloxacin in human urine.