Harmonic　nonlinear　ultrasound　can　offer　high　sensitivity　for　residual　stress　measurements;　however,　it　cannot　be　used　for　local　stress　measurements　at　a　point　in　space　and　exhibits　nonlinear　distortions　in　the　experimental　system.　This　paper　presents　a　feasibility　study　on　the　measurement　of　residual　stress　in　a　metal　plate　using　a　nonlinear　Lamb　wave-mixing　technique.　The　resonant　conditions　for　two　Lamb　waves　to　generate　a　mixing　frequency　wave　are　obtained　via　theoretical　analysis.　Finite　element　simulations　are　performed　to　investigate　the　nonlinear　interactions　between　the　two　Lamb　waves.　Results　show　that　two　incident　A0　waves　interact　in　regions　of　material　nonlinearity　and　generate　a　rightward　S0　wave　at　the　sum　frequency.　Residual　stress　measurement　experiments　are　conducted　on　steel　plate　specimens　using　the　collinear　Lamb　wave-mixing　technique.　By　setting　different　delays　for　two　transmitters,　the　generated　sum-frequency　component　at　different　spatial　locations　is　measured.　Experimental　results　show　that　the　spatial　distribution　of　the　amplitude　of　the　sum-frequency　component　agrees　well　with　the　spatial　distribution　of　the　residual　stress　measured　using　X-rays.　The　proposed　collinear　Lamb　wave-mixing　method　is　effective　for　measuring　the　distribution　of　residual　stress　in　metal　plates.