| Event | Time | Meet | Date |
|---|---|---|---|
| 100m Backstroke | 1:39.31 | 2026 Steve Kingston Memorial | 2026-03-06 |
| 100m Breaststroke | 1:54.14 | 2025 Alan Swanston Classic | 2025-12-05 |
| 100m Butterfly | 1:59.91 | 2025 Alan Swanston Classic | 2025-12-05 |
| 100m Freestyle | 1:25.24 | RHAC Winter Jr. Sprint | 2025-12-20 |
| 100m IM | 1:40.84 | 2026 Central Region Div 2 SC Championships | 2026-02-20 |
| 200m Backstroke | 3:33.38 | 2026 Steve Kingston Memorial | 2026-03-06 |
| 200m Breaststroke | 4:06.84 | 2026 Steve Kingston Memorial | 2026-03-06 |
| 200m Freestyle | 3:08.22 | 2026 Steve Kingston Memorial | 2026-03-06 |
| 200m IM | 3:33.05 | 2026 Steve Kingston Memorial | 2026-03-06 |
| 50m Backstroke | 45.18 | 2026 Steve Kingston Memorial | 2026-03-06 |
| 50m Breaststroke | 57.31 | 2025 Alex Baumann Invitational | 2025-11-21 |
| 50m Butterfly | 47.60 | RHAC Winter Jr. Sprint | 2025-12-20 |
| 50m Freestyle | 38.53 | 2026 Central Region Div 2 SC Championships | 2026-02-20 |
Geng, Jiajun's top personal bests include 100m Backstroke (1:39.31), 100m Breaststroke (1:54.14), 100m Butterfly (1:59.91), 100m Freestyle (1:25.24), 100m IM (1:40.84).
Geng, Jiajun swims for The Richmond Hill Aquatic Club.
Geng, Jiajun has competed in 9 meets.