ABSTRACTRelatively intact chloroplasts were isolated from alfalfa leaf. It was determined that the chloroplasts accounted for an average of 39.2% of the total nitrogen in the leaf tissue. When extracted with Tris‐sucrose buffer, approximately 55% of the chloroplastic nitrogen was insoluble, some 28% was soluble, and approximately 16% was nonprotein nitrogen. Thus approximately 11% of the total crude nitrogen of alfalfa leaf comes from soluble protein of the chloroplasts. During the normal process of tissue disruption to extract leaf proteins this chloroplastic soluble protein, or a good part of it, would be included in the pool of leaf soluble proteins.The distribution of nitrogen between the insoluble and soluble protein fractions and the NPN fractions was determined by extraction into a Tris‐sucrose buffer solution after sonication. Triton X‐100, sodium desoxy‐cholate, sodium trichloracetate, sodium perchlorate, trypsin, and phospholipase A were tested for their efficacy in converting insoluble to soluble nitrogen. All of these agents except phospholipase gave some improvement in the extraction of nitrogen from the chloroplasts. The, greatest increase was given by the chaotropic agent, sodium perchlorate. The perchlorate, however, interfered with the micro‐Kjeldahl procedure for nitrogen determination. Therefore, the solution had to be dialyzed before protein could be determined. Considerable amounts of NPN were obtained after dialysis which could have been produced by the action of proteolytic enzymes during the extended period required for the dialysis procedure. Trypsin increased the extraction but produced excessive amoun