Penelitian ini bertujuan untuk melakukan inventarisasi gastropoda yang berasosiasi pada ekosistem mangrove di Tapak Semarang, Jawa Tengah. Mangrove merupakan ekosistem yang memiliki peran penting, dan gastropoda sebagai salah satu komponen biotiknya memegang peran kunci dalam menjaga keseimbangan ekosistem ini. Metode penelitian yang digunakan, yaitu metode deskriptif eksploratif dengan pendekatan kuantitatif. Penelitian ini dilaksanakan dengan mengumpulkan data distribusi gastropoda pada lingkungan ekosistem mangrove. Sampel gastropoda diidentifikasi hingga tingkat spesies, dan parameter lingkungan (salinitas, suhu air, pH, DO dan substrat). Analisis statistik regresi linear dan Principal Component Analysis (PCA) untuk mengevaluasi keragaman spesies dan hubungan ekologi antara gastropoda dan ekosistem mangrove. Ditemukan beberapa spesies gastropoda yaitu Telescopium telescopium, Cerithidea obtusa, Pirenella microptera, Cassidula aurisfelis, Cassidula nucleus, Littoraria scabra, Melampus globulus, dan Cerithidea cingulate memiliki peran penting dalam menjaga keseimbangan ekosistem mangrove. Struktur komunitas pada Ekosistem Mangrove Tapak Semarang didominasi oleh gastropoda T. Telescopium dan C. cingulate. Berdasarkan penelitian yang dilakukan dapat diketahui rentang Indeks Keanekaragaman 0,20 – 1,47 (keanekaragaman rendah), Indeks Keseragaman 0,09 – 0,47 (keseragaman rendah – sedang), Indeks Dominasi 0,26 – 0,85 (dominasi rendah – tinggi). Jumlah mangrove mempengaruhi kepadatan gastropoda sebesar 57%, sedangkan faktor lain yang mempengaruhi kepadatan gastropoda sebanyak 43%.Title: Inventory Of Gastropods Associated With Mangrove Ecosystem In Tapak Semarang, Central JavaThis research aims to carry out an inventory of gastropods associated with the mangrove ecosystem in Tapak Semarang, Central Java. Mangroves are an ecosystem that has an important role, and gastropods as one of its biotic components play a key role in maintaining the balance of this ecosystem. The research method used is an exploratory descriptive method with a quantitative approach. This research was carried out by collecting data on the distribution of gastropods in the mangrove ecosystem. Gastropod samples were identified to species level and environmental parameters (salinity, air temperature, pH, DO and substrate). Statistical analysis of linear regression and Principal Component Analysis (PCA) to trigger species diversity and ecological relationships between gastropods and mangrove ecosystems. Several species of gastropods were found, namely Telescopium telescopium, Cerithidea obtusa, Pirenella microptera, Cassidula aurisfelis, Cassidula Nucleus, Littoraria scabra, Melampus globulus, and Cerithidea cingulate which have an important role in maintaining the balance of the mangrove ecosystem. The community structure in the Tapak Semarang Mangrove Ecosystem is dominated by the gastropods T. Telescopium and C. cingulate. Based on the research conducted, it can be seen that the Diversity Index range is 0.20 – 1.47 (low diversity), the Uniformity Index is 0.09 – 0.47 (low – medium diversity), the Dominance Index is 0.26 – 0.85 (low – tall). The number of mangroves influenced gastropod density by 57%, while other factors influenced gastropod density by 43%.