Aiming at a better understanding of L2 learning problems resulting from L1 and L2 timing control differences, we analyzed the differences in generation of geminate and singleton consonants which has been known to be a L2 learning problem between Japanese natives and Chinese learners. These differences were analyzed by applying tempo normalization to raw segmental duration measurements. To get a systematic understanding of L2 learners' time control characteristics, speech data of learners with different proficiency and syllable structures was employed. Analyses clearly showed that (1) timing control differences between natives and L2 learners gradually decrease as the learners language proficiency increases, (2) the differences between natives and L2 speakers show big variations depending on the syllable structure and (3) timing control differences can be understood based on timing unit differences between morae and syllables. Based on those findings, preliminary results of a novel training method that provides additional moraic context to isolated speech samples are being presented and showed the effectiveness.