Actias artemis is a members of the family Saturniidae, also known as wild silkmoths, have impressive color and size. In 2012, estimation of Actias artemis (Lepidoptera: Saturniidae) abundance in HECRI was conducted using the mark-release-recapture (MRR) method (Jolly, 1965) from mid to late May. Seven sampling events were accomplished from 19 May, 21 May, 22 May, 24 May, 26 May, 28 May and on 30 May, during the main flight of the species. Marking was made by writing numbers in the hind wing of each individual moths. Most collections were undertaken by a team of experienced four or six researches of HECRI using light trap (mercury lamp: 250W). Seven female and 58 male moths were captured in study site. The effective population size of Actias artemis was 24.9 and heterozygosity was more than 97%. Seven marked moths were recaptured, resulting in 9.7% of recapture rate. The estimated population size of A. artemis showed a peak by 133 individuals on 22 May and then declined. The estimated adult numbers of A. artemis using MRR method from minimum 168 to maximum 5,332 (p<0.05).