。
I don't feel like studying.
Literal
Study-(dictionary form) intention [subject-が] not-exist.
~する気がない is the idiom for 'don't feel like doing X,' 'have no intention to X.' 気 ('spirit, mood, intention') + がある/ない expresses having or lacking the inclination. The positive ~する気がある = 'feel like doing.' A very common expression of motivation (or lack thereof).