Parity-violating spin rotation of neutrons in a 1 3 9 La target was observed in the vicinity of the 0.734 eV p-wave resonance. The measured angle of rotation, φ p n c (E), shows a large enhancement around the resonance. The data are fitted with a theoretical function from the s-p mixing models of the parity-violation enhancement, yielding a parity mixing matrix element xW = 1.04 ± 0.40 meV which is in agreement with those previously obtained from the longitudinal asymmetry in the p-wave resonance cross section.