Horizontal gene transfer (HGT) is believed to be important mechanism for the attainment of genetic plasticity in many species of bacteria and is defined to be the movement of genetic material between cells other than by descent in which information travels through the generations as the cell divides.HGT events were reported not only in bacterial species but,trough bacterial intermediation,also in animals and plants cells.It is highly desirable to distinguish genes acquired by HGT from the whole pool of genes of the given species.With the progress of genomics and bioinformatics a vast amount of sequence data is now available which makes possible analyzing the general characteristics such as Codon Usage or GC content on the genomic scale.To study heterogeneity of those characteristic one various statistical methods were used,such as factor or corresponding analysis,principal component analysis,Mahalanobis distance,L2 distance etc.One of the group of genes suspected to be horizontally transferred are bacterial CLCA genes.CLCA were primarily characterized as calcium activated chloride channels,but after bioinformatics analysis it turned obvious that these proteins are rather related to zinc proteases.The Pfam CLCA proteins family is spread in many eukaryal species and present also in few archeal and bacterial genomes.We used database consisting of CLCA sequences and whole bacterial genomes to test known methods of HGT events identification and to propose some new approaches.