PROBLEM TO BE SOLVED: To provide a drug coating layer that can prevent a drug from coming loose and falling in the delivery manipulation passing a body cavity such as a blood vessel, when a drug is coated on a medical instrument and delivered in the body, and/or the drug coating layer that is superior in drug migration characteristics to a target tissue, and a method for controlling a morphological form of the drug coating layer.SOLUTION: A drug coating layer formed on a substrate surface is the drug coating layer selected from a group comprising the following third morphological form and fourth morphological form, and having at least one morphological form of a water insoluble drug. In the drug coating layer, (3) the third morphological form has a reticulated small incomplete crystal at least in a portion, and (4) the fourth morphological form has an acicular or rod-like, or spherical crystal at least in a portion. The third morphological form and the fourth morphological form contain the same or different drug. The emergence of the third morphological form and the fourth morphological form can be controlled by changing formation conditions of the drug coating layer.
