The problematic of reinforcement bars splicing by overlap tying and by the way of welding is described, as well as alternative splicing by the mechanical compression couplers as a way of its solution. Lap splicing showed good results in structures with small nominal dimensions of steel bars, low rate yield strength and in buildings not higher than 15 floors. Welding is the more flexible method of steel bars splicing but its use brings to rising costs and complicity of construction work. The quality of welded splices depends on many factors mainly on the existing problems in welding process. The analysis of world construction practice shows a more reliable, technological and effective way of splicing reinforcement bars it means the use of connecting couplers i.e. mechanical rebar coupling. Successful international experience of applying mechanical steel bars splicing in USA, Japan, China, Kazakhstan, UAE, etc. is described. It must be noted that with the advance of the enactment of DBN V 2.6-98 and DSTU B V.2.6-156, standard acceptable methods of steel bars splicing in Ukraine are lap splicing, welded connections and mechanical splicing. General technical requirements of the connections of reinforcement were analyzed and systematized, as well as general advantages of mechanical splices were proved. Analysis of international and native regulations showed that in Ukraine it should be taken more strict requirements for mechanical splices. Methodology and test results of mechanical splices were covered. A number of regulation documents were developed as a result of large scale theoretical and experimental research of mechanical connections. The technology of coupling of reinforcement bars was applied at many construction projects as well as in seismic regions.