Provided are full human anti-PD-L1 antibodies or fragments thereof. In various examples, the antibodies or fragments thereof include a VH CDR1, a VH CDR2, a VH CDR3, a VL CDR1, a VL CDR2, and a VL CDR3 which are selected from sequence groups of SEQ ID NO: 35-42, SEQ ID NO: 43-51, SEQ ID NO: 52-66, SEQ ID NO: 67-79, SEQ ID NO:80-88 and SEQ ID NO: 89-102, respectively, or variants of each thereof. Methods of using the antibodies or fragments thereof for treating and diagnosing diseases such as cancer and infectious diseases are also provided.