In　order　to　conduct　and　accurate　evaluation　on　the　joint　quality　of　spot　welding　by　using　ultrasonic　echo　transmitting　signals,　a　software　system　of　ultrasonic　inspection　and　joint　quality　evaluation　has　been　developed　on　the　platform　of　VB6.0.　The　software　system　achieves　the　transmission　and　storage　of　the　data　of　ultrasonic　signals　in　the　digitab　oscilloscope　by　calling　TekVISA　ActiveX　controllers　supplied　by　Tektronix　Inc..　Based　on　the　principle　of　ultrasonic　inspection　for　joint　quality　of　spot　weld,　a　proper　evaluation　on　the　joint　quality　of　spot　weld　can　be　carried　out　by　selecting　and　calculating　the　main　characteristic　parameters.　The　software　has　a　friendly　interface　and　can　be　operated　easily.　It　has　been　proved　that　the　evaluation　rule　is　correct,　so　the　software　can　be　applied　to　the　ultrasonic　inspection　and　evaluation　for　joint　quality　of　spot　weld.