An angle-adjustable aroma diffuser, comprising:
a housing defining a first opening and second opening opposite to said first opening;
an aroma container mounted in said housing for holding an aroma substance, said aroma container defining a top open side facing toward said first opening of said housing;
a resistor provided at a bottom side of said aroma container and adapted for creating heat to heat an aroma substance being put in said aroma container; and
an electric plug pivotally coupled to said second opening of said housing and electrically connected with said resistor.