Based on dependency syntactic treebanks, the present study focuses on relative clauses (RCs) and explores their relations between dependency distance (DD), dependency direction, the embedding position, and the length of RC. It was found that: (1) the probability distributions of the DD of RCs aren't influenced by their embedding positions; (2) the DD of RC embedded in the object position is relevant to the length of the RC; (3) the longer the RC is (≥10), the more likely the dependency relations within the RC present a head-initial tendency; (4) the embedding positions of RCs in main clauses don't influence their dependency directions and dependency directions of RCESs and RCEOs are almost head-initial; (5) the changes of dependency relations of main clauses are related to the embedding position of relative clauses; (6) the embedded RCs increase the MDDs of their main clauses significantly.