We study the moduli space of genus 3 hyperelliptic curves via the weighted projective space of binary octavics. This enables us to create a database of all genus 3 hyperelliptic curves defined over Q, of weighted moduli height h = 1.2000 Mathematics Subject Classification. Primary 54C40, 14E20; Secondary 46E25, 20C20.Then, the following (2)are SL 2 (k)-invariants. There is another invariant J 14 which is the discriminant of the binary form f (X, Y ). For the purposes of this paper we will denote ∆ = J 14 .Theorem 1. The graded ring R 8 of invariants of binary octavics is generated by elements J 2 , . . . , J 10 .J 4 = 2 9 · 3 · 7 4 · (k, k) 4 , J 5 = 2 9 · 5 · 7 5 · (m, k) 4 , J 6 = 2 14 · 3 2 · 7 6 · (k, h) 4 , J 7 = 2 14 · 3 · 5 · 7 7 · (m, h) 4 , J 8 = 2 17 · 3 · 5 2 · 7 9 · (p, h) 4 , J 9 = 2 19 · 3 2 · 5 · 7 9 · (n, h) 4 ,