This article examines the relationship between sentential subjectival position and sentential syntactic complexity using the written section of the ICE-GB as the data source. The information the subject bears is generally regarded as given, with new information provided by other functional classes after it. This means that generally the part of the sentence after the verb would more elaborate, hence longer, than the one before it, manifesting the principle of end weight. Since the English language is basically an SVO language, this seems to suggest that the position of the subject in the sentence would have a certain relationship with sentence length, hence sentence complexity. The result shows the relationship between sentential syntactic complexity and sentential structural variation in number of sentences with different structures is bell-shaped, which can be described with Nemcová and Serdelová's synonyms and word length model. The sentential subjects appear in 46 different positions in the sentence, but the predominant position is sentence initial. Generally, the sentential subjectival position is an indicator of sentential syntactic complexity; the larger the sentential subjectival position, the more syntactically complex the sentence. This phenomenon, apart from rhetorical and stylistic reasons, is due to the principle of end weight and communication dynamism in the sentence.