I'll quote the AP story:
China said Wednesday that the detention of Myanmar democracy leader Aung San Suu Kyi is an internal matter for the Southeast Asian country's government, declining to join other nations urging her release.
China's stance came a day after the 10-country Association of Southeast Asian Nations, or ASEAN, broke with its core policy of noninterference and pointedly called on Myanmar's military-backed government to release Suu Kyi, a Nobel Peace Prize laureate.
China's Foreign Ministry said in a statement that "the Aung San Suu Kyi matter is Myanmar's internal affair. The Chinese side hopes to see Myanmar maintain political stability and continue to make progress in the process of national reconciliation."
China and Russia both vetoed an American-sponsored resolution in the Security Council of the UN calling for an end to political suppression in Myanmar. Naturally, those two bastions of endemic political suppression really don't want to be setting precedents against these policies.
Notably, the other members of ASEAN include nations not traditionally thought of for their human rights records, such as Vietnam and Indonesia. Even they, however, are more concerned with Aung San Suu Kyi's situation than with reinforcing a precedent of allowing suppression. I'll take that as a good sign.