This diploma thesis deals with the topic of phylum cnidaria as it is being taught in biology classes at primary schools and grammar schools. This work is divided into three parts. The first part deals the position of the topic of phylum cnidaria among curricular documents. It states its classification in the Czech Framework education programme (for Elementary Education) and some chosen School Education Programme. Furthermore, this part analyses the topic as it is written in biology class books, with the clause by the Ministry of Education, Youth and Sports of the Czech Republic. Representatives of phylum cnidaria that are mentioned in biology class books are characterised more thoroughly within the scope of the analysis. The second part of the thesis deals with the teaching methods and forms that are used in teaching biology the most frequently and the questionnaire research that tells us which forms and methods are being used the most by teachers to teach about phylum cnidaria and what specific activities they employ in class. The last part of the thesis consists of suggestions for practical activities for teaching the topic of phylum cnidarian inspired by the results of the survey and a description of educational excursion to the World of Jellyfish aquarium with 6th grade pupils. KEYWORDS phylum...