The only book currently available to learn Sinhala grammar is Sidath Sagara. This was written in the thirteenth century. Sidath Sagara talks about gender, only two genders as masculine and feminine nouns. Although Sidath Sagara says that there are two genders, according to the Sinhala practice, three genders are implemented. The third gender is the neuter gender. Sinhala gender has been introduced after paying attention to the gender difference in Pali and Sanskrit languages. Understand gender discrimination in Sidath Sagara without knowledge of Pali and Sanskrit languages. This is a problematic situation. Because of this, scholars refuse to explain the gender of the Sidath Sagara. Some people justify sidath Sagara's gender bias. This research was carried out in order to properly investigate Sidath Sagarava's gender examination and arrive at conclusions. why neuter gender is not valid in Sinhala in Sidath Sagarava's gender examination? is kept as the research problem. The main objective of the research was to study gender discrimination in Sidath Sagara. Studying the various ideologies that have been presented regarding gender discrimination, Sidath Sagara's research on gender and reaching balanced conclusions began. Sidath Sagara was kept as the primary source. Various editions of Sidath Sagara, Sinhala grammar books and Journals written in this regard, newspaper articles etc. were the secondary sources by studying the gender difference in Sidath Sagara and grammar tradition of Sinhala, it was kept as the basis of the research that the existing problems regarding gender discrimination in Sidath Sagara will be resolved. the research sample was only for the work of Sidath Sagara and Sinhala grammar tradition. From the data analysis of the research 1. Gender distiction as discrimination in Sidath Sagara is a gender discrimination used for poetry 2. the author of Sidath Sagara explains focusing on the gender distinction in Pali and Sanskrit languages and not focusing on the Sinhala language. 3. it is uncinded the three conclusions that Sidath Sagara's gender distinction is a traditional Sinhala grammatical tradition.