At the embryonic development, signal transduction pathways, genetic factors, involvements between nucleus and cytoplasm, environmental factors, cell-cell and cell-matrix interactions have important roles. It has been known that the cells are regulating the Extracellular Matrix (ECM) synthesis, degradation and reshaping events, also it has been known that the Nitric Oxide is an important molecule for cellular communication and have effects on ECM molecule distribution by reacting with ECM molecules. In this reason, the purpose of our study is detecting the correlation of reactive nitrogen species with a glycosylated molecule laminin α1. In this experiment, Leghorn type SPF (Specific Pathogen Free) embryonic chick eggs have been used. Embryos are collected at 5 th , 6 th and 7 th days at incubation and taken into the 10% neutral buffered formalin solution. The liver tissues that dissected from embryos are fixated at second time. After 24 hours, it has been subjected to the routine paraffin embedding method and embedded to paraffin. From the 5µm sections, immunohistochemistry for eNOS, iNOS and Laminin α1 distribution, and for general histologic evaluation, Haematoxylene-Eosin stains has been applied. eNOS and iNOS immunoreactivity has been observed at peripheral zone of developing liver tissue that epithelialmesenchymal transition takes place. It has been determined that immunoreactivity was minimal in 5 th day, increasing with the days progressed and have highest at 7 th day. Also, eNOS staining has been more powerful than iNOS staining. Laminin immunoreactivity has been similar at all developmental stages, but relatively, has been showed lesser staining. Particularly, the presence at the zones of cell differentiation has been noteworthy.