Bacterial　antibiotic　resistance　genes　(ARGs),　a　kind　of　emerging　environmental　pollutants,　greatly　threat　human　health　through　pathogenic　bacteria.　High-throughput　quantitative　PCR　(HT-qPCR)　and　metagenomic　approaches　are　two　popular　tools　applied　in　aquatic　environmental　ARGs　monitoring.　However,　current　poor　knowledge　of　different　ARG　profiling　approaches＇　impacts　on　the　understanding　of　the　ARGs　in　aquatic　environments　greatly　limit　the　further　field　application　of　these　two　approaches.　For　filling　such　knowledge　gap,　this　study　simultaneously　employed　these　two　approaches　to　examine　and　compare　the　ARGs　in　a　freshwater　reservoir　across　space　and　time.　We　found　metagenomic　approach　detected　more　ARG　subtypes　and　much　higher　bacitracin　resistance　genes＇　abundances　than　HT-qPCR.　In　general,　HT-qPCR　and　metagenomics　analyses　both　revealed　similar　ARG　dynamic　patterns　and　co-occurrence　patterns　between　ARGs　and　bacterial　taxa　as　well　as　the　relationships　between　ARGs　and　environmental　factors.　Our　results　indicated　the　impacts　of　different　ARG　profiling　approaches　on　the　understanding　of　bacterial　ARGs　might　be　minor　or　negligible.　HT-qPCR　approach　has　the　superiorities　of　time-saving,　absolute　quantification,　low　requirement　for　bioinformatics　skills　but　also　has　some　drawbacks　including　higher　PCR　amplification　&　primer　bias,　higher　primer　dependency　and　relative　lower　ARG　subtype　quantification　capability　compared　to　metagenomic　approach.　We　suggest　HT-qPCR　approach　can　be　employed　for　routine　aquatic　environmental　monitoring,　and　metagenomic　approach　could　be　applied　in　comprehensive　surveys　for　getting　more　ARG　subtype　information.　Our　data　can　be　a　useful　reference　for　choosing　right　ARG　pro-　filing　approaches　for　bacterial　ARGs　monitoring　and　risk　assessment　in　aquatic　environments.　(C)　2019　Elsevier　B.V.　All　rights　reserved.