Inclusion Criteria:  The PWD must satisfy the following criteria to be included in the study:  60 years old or above residing at home with a diagnosis of dementia of any type and stage of severity presenting with at least one symptom of BPSD in the previous one month before the study able to communicate in Cantonese or Mandarin  The caregivers must satisfy the following criteria to be included in the study:  family members, partners, or relatives living with PWD provide unpaid daily care to PWD at home literate in Chinese and able to communicate in Cantonese or Mandarin.  Exclusion Criteria:  PWD and their family caregivers are excluded from the study if either of them have:  allergy or discomfort after using Lavender essential oil other neurological or psychological diseases besides BPSD the following conditions: pregnancy, breastfeeding, hypotension, exacerbation of asthma, dyspnoea, epilepsy, or glucose-6-phosphate dehydrogenase deficiency current use of the following drugs: anticoagulant Warfarin, antiplatelet Aspirin, central nervous system depressant, or anticonvulsant hate the smell of Lavender or Lavender essential oil PWD have received aromatherapy in the past one month a change in family caregiver within 1 month before the study or during the study period.