Tokyo fell 0.10%, or 14.41 points, to finish at 14,815.98 and Hong Kong was down 0.67%, or 145.87 points, at 21,756.08.
Manila eased 0.51%, or 32.68 points, to 6,429.79, Jakarta ended up 0.89%, or 41.78 points, at 4,726.17, Kuala Lumpur ended flat at 1,818.86 and Singapore closed down 0.52%, or 16.04 points, at 3,081.39.
China said industrial output, which measures production at factories, workshops and mines, rose 8.6% year on year in January and February, the slowest rate since April 2009, at the height of the global financial crisis.
At the same time retail sales, a key indicator of consumer spending, were up 11.8%, which was also the worst performance for several years. However, the news adds to speculation the Chinese economy -- a crucial driver of regional and global growth -- is slowing and comes days after officials announced a surprise trade deficit in February, which sent world shares tumbling.
Zhou Hao, Shanghai-based economist for ANZ bank, called the data "a complete mess" and said it showed that policies were needed to spur growth.
"Basically none of the figures were in line with expectations, all came in much lower than expected," he told AFP.
And ANZ economist Liu Ligang told Dow Jones Newswires: "It is time for the government to consider some loosening, either fiscal or monetary, to sustain growth."