Control of the welded compounds is pronouncedly substantially territory of technology because of the widespread use of welded compounds in engineering. For that reason, it is substantially that compound is correct and that satisfies all conditions users are expecting. Of course, nothing is perfect, neither are welded compounds, but it is substantially to notice deffects, if there are, before using products, therefore conducting tests are necessary in order to prevent unwanted weld cracking or similar. Welded compounds can be tested with destructive and non-destructive methods. In this final work will be made analysis tests of the welded compounds with non-destructive methods. Non – destructive methods are very appreciated because of their widespread use in praxis, for various kinds of surface and subsurface deffects, and besides that they do not damage tested product or semi product, actually, with using NDT methods of testing it is not affecting on functionality of the tested object. Non-destructive methods (NDT) are also named defectoscopy. NDT methods can follow the product of raw material through semi product, and to final product. Testing without destructing (defectoscopic testing) are usually conducting with two NDT methods minimal, with supplement of one destructing test depending on product to be tested and characteristics that are required to be tested. Non-destructing testing are conducting with plenty of methods. Method is selected according to type of tested objects, deffects we are looking for or equipment for conducting tests. Testing of welded compounds is conducting with: Visual method (VT), Magnetic control (MT), Ultrasonically control (UT), Radiographic control (RT) and Penetrant control (PT) which is the main case of consideration of this work. Penetrant testing (PT) is one of the early methods of control without destructing and on its way it is the extension od visual control because deffects are detected by eye, with microscope or similar. PT has very wide using in praxis because of many possibilities and relatively low cost of test conducting. Experimental part of this work describes test conducting of welded compound by penetrant control (PT). Experimental part includes test preparation, test procedure, deffect detecting, analysis and conclusion.