Theoretically, as long as the kissing time is long enough or both parties have broken oral mucosa or broken lips or bleeding, and the blood or body fluids are exchanged between them, it is possible to get infected. But in fact the world has not seen a clear case of HIV infection because of kissing, ordinary ritual kissing is not a problem, if it is a French-style deep kissing, and sometimes there are even kissing competitions, really to catch both people have broken, can only say that theoretically this risk still exists, but this kind of kissing way ordinary people are unnecessary to worry about, because you can not have so long kissing, so kissing can be considered not to transmit AIDS.