Spontaneous symmetry breaking and the Weinberg-Salam model have been reform
ulated in terms of quaternion-valued field variables. The quaternion-valued
scalar Lagrangian reduces to four different field equations associated wit
h the scalar quartet (phi(0), phi(1), phi(2), phi(3)) Of it quaternion fiel
d phi = phi(0) + e(1)phi(1) + e(2)phi(2) + e(3)phi(3). It has been shown th
at the quaternion gauge group SO(4) is spontaneously broken to two gauge gr
oups of SU(2) non-Abelian gauge fields. The Weinberg-Salam model of electro
weak interaction has been extensively studied to enlarge the gauge group st
ructure SU(2)L x SU(2)(R) x U(1).