Applying PhD during the last year of master studies I am a final year master student and currently I am working in my thesis (I have done about 70% of my work).  My graduation will be expected to be latest in this August.
I have published several publications during my bachelor degree.  However, I have not published any single publication during my master studies (my supervisor has a plan to publish a paper based on my thesis works).
Is it possible for me to apply for a PhD studies with stated condition above (I haven't get master degree and lack of publication in my master degree.
In addition  I do my bachelor and master thesis in different subfield. I will plan to take a PhD in the same subfield as my master studies. So I can say I dont have any publications directly related to my planned PhD studies.
You can definitely apply. If not now, then when?
The number of publications doesn't matter that much because the number is just a number; it doesn't reflect the complexity or difficulty of the research you did. I would fully expect that the publication resulting from your Masters studies will be more substantial - i.e., involve more work, with more robust results - than those you did during your Bachelor's.
If it still troubles you, remember there are people who do PhD studies without having published any papers in the past,