Abstract: Lacertid lizards,Eremias brenchleyi were captured from field,and reared artificially.Laid eggs were incubated at 30 ℃ and -12 kPa (humidity).Whole eggs,eggshells,yolks,and embryos were weighed,and energy of certain components was determined at a series of time points.Data on the development of embryos and the transition of material and energy in eggs incubation were processed,resulting in:1)The duration of incubation averaged 35 days,and the egg in wet mass increased for absorbing moisture while incubating.2)The embryos employed about 10%,30% and 20% of the total egg energy in the periods of 0-20,20-30,and 30-35 days of incubation,respectively.3)The embryos grew slowly during the first 20 days,then grew rapidly.4)Approximately 63.4% dry material,32.7% non-polar lipids and 59.6% energy in the contents of fresh eggs were transferred to the hatchlings.5)Inorganic material in both yolk and eggshell was used by the embryos in development.The transition ratios of dry material and non-polar lipids as main energy-substance,and the proportion of residual yolk in hatchlings are lower than those reported for snakes.The lower ratios maybe related to the longer slow-phase of embryonic development in this species.