In Article 37 of Law No. 193, commercial gain is defined as "profits arising from all kinds of commercial and industrial activities". The commercial or industrial activity has not been defined in the relevant article and has not been referenced directly any other citation. The concept of commercial and industrial activity is generally determined by using the characteristics of the commercial business in the Turkish Commercial Code. One of the characteristics of a commercial business is continuity. In terms of Income Tax, continuity is considered as the determinant of casual earnings and commercial earnings. In this study the continuity is discussed both in terms of trade law and income tax. As a result of the evaluations made, it has to be determined whether the existence of the continuity should be determined by targeting the commercial purpose according to the characteristic of the event rather than the objective criteria.