I will depart from Pula to venice at 10/6 (FRI), which don't have ferry to Venice.
So, I must take a bus from Pula, however I am not sure about the destination.
I saw there are Trieste, I am wondering where is the Trieste bus station, if I can connect to train easily? How much is the fare going from Trieste to Venezia Santa Lucia?

I also found someone said there is a bus arrive Venezia Santa Lucia/MESTRE, only available on the first bus of the day (which is 5am depart from Pula) isn't it? I am doubt about that.

Take a bus to Trieste, the train station is then close by.

We took the early bus from Rovinj to Venice. I believe the bus originally came from Pula and stopped in Rovinj. We made a stop in Trieste, but didn't change buses, and continued on to Venice.

This could have changed, of course. This is just to let you know that there was an early bus that went to Venice.

Thanks for the info.
And I checked the schedule, It is better for me to take the bus at 5am, which I can arrive Venice directly.

If I need to buy the ticket in advance? How much is it?
Thanks

I ask the bus company though email and
They reply me:
bus leaves from Pula bus station (Trg Istarskih brigada) every day except Sunday at 05,30 and arrives to Venice bus station (Piazzalle Roma) at 10,45.
Price is 171,00kn or 24 EUR.
You can make reservations by email few days in advance and buy ticket in bus.

did this last year the bus station is right next to

the train station at Trieste so bus to Trieste

walk across the street to the train station

hop the regional train to Venezia 4 euro for me last year

couple of hours with stops as I recall not bad at all.