Novel human immunoglobulin V.sub.H segments and DNA fragments containing the same are disclosed. The DNA fragment according to the present invention is the fragment having a size of about 800 kbp which is shown in FIG. 1. The human immunoglobulin V.sub.H segments according to the present invention are contained in the fragment of this DNA fragment of about 800 kbp, and there are 50 novel segments. The base sequences of these :segments are shown in the Sequence Listing. The present invention also provides DNA fragments which contain two or more of these V.sub.H segments.