This longitudinal investigation examined the developmental sequence of syntactic acquisition in seven children during the early syntactic period. The collected corpora were analyzed according to a hypothesized simplicity-complexity dimension based on the number of grammatical relations produced and the expansion of these relations. The hypothesized simplicity-complexity dimension was largely upheld and specified a sequence of acquisition which was observed in the data from all children. The application of this dimension, based on the basic grammatical relations, examined developing syntactic complexity independently of but consonant with adult linguistic descriptions. The syntactic constructions were also analyzed according to the semantic categories expressed. The semantic analysis revealed generalized developmental trends.