The invention relates to an antidepressant effect and application of effective parts of hypericum wightianum. The extraction and separation method of the effective parts of the hypericum wightianum comprises the following steps: degreasing the hypericum wightianum; extracting with a water-alcohol liquid which is prepared from methanol, ethanol, propanol or n-butanol and water with alcohol amount of 0-80%; separating a concentrated solution with resin column chromatography; and carrying out antidepressant pharmacodynamic screening on various separation parts so as to find a separation component with a good antidepressant effect. In the specific embodiment, the component can obviously shorten the immobility time of mice in a tail suspension test and the immobility time of the mice in a forced swimming test, can obviously inhibit mice hypothermia caused by reserpine, and can obviously increase the evasion times of the mice in a learned helplessness test. The effective component of the hypericum wightianum has obvious antidepressant effect, can be used for preparing antidepressant preparations, or used for studying a specific compound in the component and developing antidepressant monomer compound preparations.