Objective  To explore the peroxidation of rat liver after microwave acute or chronic irradiation and investigate the protective effects of micronutrient intervention in the injury. Methods  Eighty Wistar rats were randomized into sex and weight-matched groups according to being fed with common chow or supplemental micronutrients (VitC

VitE

Na

2

SeO

3

and ZnSO

4

·7H

2

O are 0.5

0.25

0.

44 and 219.87 mg/kg respectively). Each group was further divided into 5 subgroups

that is

sham exposure group

chronic microwave irradiation (15 mW/cm

2

20 min/d

for 8 weeks)

and 3

24 and 72 h after acute microwave irradiation groups (65 mW/cm

2

20 min). Rats of sham exposure group and chronic irradiation were fed with the corresponding diet during the irradiation

while those of acute irradiation groups received the irradiation after fed by the corresponding diet for 8 weeks. The apoptotic changes of hepatocyte were observed with TUNEL. The peroxidation damage by microwave and the protective effect of micronutrient intervention were detected by measuring SOD

MDA

GSH-Px and reactive oxygen species (ROS) in the liver tissues.  Results  Acute and chronic microwave irradiation induced the apoptosis of hepatocyte (

P

<

0.01)

and micronutrient intervention decreased the number of apoptotic cells (

P

<

0.05). The acute and chronic microwave irradiation induced the oxidative stress by decreasing SOD and GSH-Px activity

reducing the activity of scavenging hydroxyl radical

and increasing the content of MDA obviously (

P

<

0.05

P

<

0.01)

while micronutrient intervention reduced these peroxidation damages significantly (

P

<

0.05). Conclusion  Acute and chronic microwave irradiation initiates oxidative stress in the liver

which is one of the main mechanisms of microwave bioeffect. Micronutrient intervention has protective effect on the peroxidation damage induced by microwave irradiation.