The Parliament of Indiamakes,amends, and unmakeslaw. The Supreme Court of India (from now on,theSupreme Court), under Article 141 of the Constitution of India, declares the law and makes and unmakes the law while deciding cases through the process of judicial review and interpretation-construction. The constitutional powers of these two branches are related but separate. The law made by the Parliamentstands constitutionally valid unless declared unconstitutional, eviscerated or read down by the Supreme Court. As the analyses reveal, the 1theconstitutionality of none of the seven intellectual property (from now on, IP)enactments has been challenged before the Supreme Court in any of the cases brought before it. Had the constitutionality of these statutes been challenged even challenged,, the statutes are presumed to be constitutionally valid, and the person who challenges the statute's validity and any provision thereof has a heavy burden to discharge. The Supreme Court ordinarily interprets-constructs the statute's provisions and applies them the same to decide the question(s) of law and/or question of factsin a lisbetween the parties before it. The answer of the Supreme Court becomes binding not only in persona but also in rem for future cases. Among all the IP cases decided by the Supreme Court, trademark law may be called the king of IP decisions with maximum number of reported decisions followed by copyright, patent and design laws. The first trademark case was decided by the Supreme Court in the year 1953, after 1196 days (3.27 years) of its establishment. In 20th century, the Supreme Court decided a total of 19 cases on trademark law. On an average, the Supreme Court has decided .38(point three eight)trademark cases in a year, one trademark case in 978.94 (point nine four) days or in 2.68 (point six eight) years. A review of reported decisions of 20thcenturyreveals that the Court has: (i) declared Trademark Law in 15 decisions; (ii) not only interpreted the provisions of the statutes but has also constructed them; (iii) not declared anything on the constitutionality of the trademark statutes as no such question of constitutionality was involved; (iv) delivered all the decisions unanimously as no dissenting or concurring judgment is reported; (v) decided maximum number of cases full Bench (11) and remaining 8decisions division Bench. It is also observed that two Chief Justices of India and one Acting Chief Justice were on the Bench in three decisions, but the judgment was authored only by the Acting Chief Justice. Paper proceeds with the same argument and method as developed and adopted in the first three papers covering patent law, copyright law and design law published under the theme „IP Laws Declared by the Supreme Court‟.This Paper seeks to cull out the principles of trademark law as declared by the Supreme Court in 20thcentury decisions