The present invention belongs to the field of medicines and daily chemicals, and relates to use of cannabidiol or cannabis extract in preparation of skin whitening products. Specifically, the present invention relates to use of any one selected from (1) and (2) in preparing medicines or reagents for inhibiting the activity of tyrosinase, inhibiting melanin formation or inhibiting melanocyte generation : (1) cannabidiol or pharmaceutically acceptable salts or esters thereof; and (2) a plant extract containing cannabidiol. The cannabidiol or the cannabis extract can effectively inhibit the activity of tyrosinase, and has a good skin whitening effect.