Calabi-Yau varieties and Fano varieties are building blocks of varieties in the sense of birational geometry. They are expected to satisfying certain finiteness. Recent progress on BAB Conjecture shows that certain Fano varieties form a bounded family. We are looking for the analogue for Calabi-Yau varieties. We only consider rationally connected Calabi-Yau varieties with klt singularities, which are those Calabi-Yau varieties behaving most like Fano. We show that rationally connected klt Calabi-Yau 3-folds form a birationally bounded family. This is a joint work in progress with W. Chen, G. Di Cerbo, J. Han, and R. Svaldi.