The pathological and histochemical changes inthe lung of ten guinea pigs have been investigated after using viable Nocardia asteroides in a dose of 1.5*108 cfc, thebacteria was injected intrapulmonary. Lesions of pyogranuloma were developed. Histochemical studies showed that the granules of goblet cells and mucos glands of lung contain a mixture of neutral and sialomucin normal animal , these types of mucin changed to sialomucin and sulfomucin inthe infected animals.