The effect of an specific immunoglo- bulin to meningococcus group A was tes- ted in rabbits infected with meningococcus group A and yielded satifactory results All the 10 rabbits in the treated group appeared normal, while 5 of the 12 rabbits in the control group developed toxic symptom and DIC, and 2 died finnally. The immunoglobulin was then appli- ed clinically to 4 children with meningo- coccal meningitis. Three of them recove- red. Unfavorable outcome was found in the fourth patient, in whom meningococ- cus group B was isolated from his blood and CSF. Since meningococcus group A continues to be the predominant pathogen in our country, the above-mentioned study provides strong support for the adminis- tration of specific immunoglobulin to chil- dren with meningococcal meningitis.