The research aims was to reveal information on biology reproduction of Indian mackerel caught in the waters of northern Aceh (part of the Strait of Malacca). Sampling was carried out at two locations, namely in the Port Fishery Coast (PPP) Lampulo, Banda Aceh and in the PPP Idi Rayeuk. Fish were sampled at PPP which originating from northern waters of Lampulo Banda Aceh in March, June and November 2009, while the fish samples from the PPP Idi Rayeuk caught from east of Sabang/Weh Island waters in March and June 2009. Number of samples taken at each sampling ranged from 40 to 60 fish with the smallest of forked length (FL) was 14 cm. Biological aspects of fish that were observed included forked length, weight, sex, gonad maturity (TKG), gonad weight, fecundity, and egg diameter. The results showed that the first maturity size (Lm) of Indian mackerel female in the waters of northern Aceh was 19.97 cm (FL), fecundity ranged from 300,000 to 520,000 eggs and fish egg diameters ranged from 144 to 588 ^m. AbstrakPenelitian ini bertujuan mengungkap informasi reproduksi ikan banyar yang tertangkap di perairan utara Aceh (laut dalam, bagian dari Selat Malaka). Pengambilan ikan contoh dilakukan di dua lokasi, yaitu di Pelabuhan Perikanan Pantai (PPP) Lampulo, Banda Aceh dan PPP Idi Rayeuk. Ikan contoh yang disampling dari PPP Lampulo berasal dari perairan utara Banda Aceh pada bulan Maret, Juni dan November 2009; sementara ikan contoh dari PPP Idi Rayeuk tertangkap dari perairan timur laut Sabang/Pulau Weh pada bulan Maret dan Juni 2009. Jumlah ikan contoh yang diambil di setiap pengambilan contoh berkisar antara 40-60 ekor ikan dengan panjang cagak (FL) terkecil 14 cm. Aspek biologi ikan yang diamati meliputi panjang tubuh, bobot, jenis kelamin, tingkat kematangan gonad (TKG), bobot gonad, fekunditas dan diamter telur. Hasil penelitian menunjukkan bahwa ukuran pertama kali matang gonad (Lm) ikan banyar betina di perairan utara Aceh sebesar 19,97 cm (FL), fekunditas sebesar 300,000-520,000 butir telur dan diameter telur ikan berkisar antara 144-588 ^m.