Abstract: Firstly, a class of entanglement-assisted quantum codes with parameters ［［n+l,k-h,d′;n-k-h+l］］ are constructed by using an orthogonal basis of the linear complementary dual (LCD) linear subcode of the classical linear code C with parameters ［n,k,d］over a finite field F_q, where h=dim(Hull_E(C)), 0≤l≤k-h, d≤d′≤d+l. In particular, when the classical linear code C is Euclidean dual-containing linear code, there are entanglement-assisted quantum codes with parameters ［［n+l,2k-n,d′;l］］, where 0≤l≤2k-n, d≤d′≤d+l. Secondly, by making a kind of transformation on the parity check matrix H of Euclidean dual-containing linear code C with parameters ［n,k,d］, another kind of entanglement-assisted quantum codes with parameters ［［n+l,2k-n+l,d′;2l］］ are constructed, in which 0≤l≤n-k, d≤d′≤d+l.

Key words: entanglement-assisted quantum codes, Euclidean duality, LCD codes, parity-check matrix, linear codes