All the following veins drain into internal jugular vein except
Retromandibular vein
Internal Jugular vein

It is the continuation of sigmoid sinus
Tributaries of IJV

1. Inferior Petrosal sinus
2. Ferial
3. Lingual
4. Pharyngeal
5. Superior thyroid vein
6. Middle thyroid vein
Facial vein
Lingual vein
Retromandibular vein
Superior thyroid vein