The applicability of Amino–functionalized Fe3O4 nanoparticles (NPs) as an effective adsorbent was developed for the extraction and determination of clomipramine (CLP) in plasma sample by ultrasoundassisted dispersive magnetic solid phase extraction (UADM-SPE) and high-performance liquid chromatography-ultraviolet (HPLC–UV) detection. Fabrication of the Fe3O4@SiO2-NH2 magnetic nanoparticles confirmed by Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The effect of different extraction parameters (i.e. pH of the sample solution, the amount of magnetic nanoparticles (MNPs), sample volume, temperature and sonication time) on the extraction recovery of CLP were investigated by response surface methodology through central composite design (CCD). The optimum condition is obtained when the affecting parameters are set to: pH of the sample solution = 9, the amount of MNPs = 37 mg , sample volume = 23 mL, 25 ℃ temperature and sonication time = 1 min. Under the optimum condition, extraction recovery was 90.6% with relative standard deviation of 3.5%, and enrichment factor of 117. The linear range for determination of CLP was 0.017 -0.70 mg L-1 with a determination coefficient (R2) of 0.999. Limit of detection (LOD) and limit of quantification (LOQ) were 0.005 and 0.0167 mg L-1, respectively. The established UADM-SPE-HPLC-UV method was rapid, simple and efficient for determination of CLP in human plasma samples.