Objective To study the effects of heroin on the structure of cerebral temporal lobe cortex and activities of adenosine deaminase (ADA)， succinate dehydrogenase (SDH)， nitric oxide synthase (NOS) and glutathione (GSH) of developmental filial mice. Methods Forty-eight pregnant mice at the eighth day began to be continuously injected with three different concentrations (1.0g/L，1.5g/L and 2.0g/L) of heroin and the same amount of saline until the birth of filial mice. Cerebral weight of filial mice was weighted. And it was observed that the changes of the cerebral temporal lobe cortex of filial mice by bio-microscopy，and detected that the activities of ADA，SDH，NOS and GSH by colorimetry at embryo 15 days and postnatal ages of 1 day， 7 days， 15 days from all experimental groups. Results The development of filial cerebral was affected by heroin. The cerebral weight of experimental group was significantly lighter than that of the control group. The structure of filial cerebral temporal lobe of experiment group was not clear. The thickness of filial cerebral decreased and the number of neurons reduced except those in the cerebral temporal lobe cortex Ⅵ at embryo 15 days and postnatal 1 day Compared with the control group，ADA，SDH and NOS activities in brain increased while GSH activity decreased significantly at embryo 15 days after administration of heroin (EM>P/EM><0.01 or EM>P/EM><0.05)，but the recovery of these activities at postnatal 15 days varied with different doses. All of these activities subsequently recovered to the normal level slowly in heroin administration (1.0g/L)；Activities of NOS and SDH also recovered to the normal level while others remained significantly affected at the dose of 1.5g/L；ADA，SDH and NOS activities were still higher and GSH activity was lower than that of the control in 2.0g/L group. Results of EM>Two-Way AN