Resistance　spot　welding　is　an　important　branch　of　the　welding　subject,　and　has　been　widely　used　in　aviation,　aerospace,　automotive　and　other　industrial　areas　due　to　its　high　efficiency,　low　cost　and　small　deformation.　As　the　improvement　of　the　product　quality,　online　monitoring　of　welding　quality　has　become　an　urgent　issue.　This　paper　puts　forward　an　information　acquisition　and　evaluation　method　based　on　the　online　monitoring　of　the　weld　quality　of　spot　welded　titanium　alloys.　Through　the　real-time　acquisition　and　analysis　of　the　welding　parameters,　the　characteristic　information　of　the　acquired　signal　was　extracted　to　achieve　the　reliable　quality　assessment　of　the　welding　process.　(C)　2016　The　Society　of　Manufacturing　Engineers.　Published　by　Elsevier　Ltd.　All　rights　reserved.