  The matrix element Vud of the CKM matrix can be determined by two independent
measurements on neutron decay: the neutron lifetime tau and the ratio of
coupling constants lambda, which is most precisely determined by measurements
of the beta asymmetry angular correlation coefficient A. We present recent
progress on the determination of these values and derive a world average of Vud
= 0.9743 (2)RC (8)tau (12)lambda.
