You probably saw Yuting (type 72 improved) class LSTs. In addition to these, the Chinese were building up a number of wing-in-ground-effect craft (sort of an aircraft-boat that "flies" just a few feet above the water) and ocean-capable air cushion vehicles (their type 724, similar to our LCAC) and putting the majority of them in storage (20 or so are deployed on the Yutings, but they have at least 4 times this quantity in storage). Combined with traditional naval assets, these units would be capable of performing an invasion of Taiwan (although probably not a successful one, see below), but not unless their quantities in storage are far in excess of what we believe them to be.
If we assume that what we "think" we know is correct, then they have about 100-150 of these "LCAC"s, each capable of carrying 10 soldiers. That is only about 1500 troops. Their ground-effect craft numbers are unknown, but it is not believed that the Guangzhou facility has started producing them in any significant numbers yet. If similar to the old Soviet designs, they would be expected to carry around 200-300 soldiers and a number of ground combat vehicles. But since we haven't seen any build up of such craft, we can assume that they have no more than a few prototypes. Assuming 5, that is still only another 1000 troops. In addition, they also have the eight Yuting class ships, each which can carry 250 troops. That is another 2000 troops. They also have seven of the earlier type 72 (Yukan) LSTs, each which can carry 200 troops. That is another 1400 troops, bringing the total to just under 6000 troops. When their Yuliang (Type 79) landing ships are added (they have around 30 of them, each with a capacity of 150 to 200 troops, although it would be a very uncomfortable ride), the total amphibious capability of the Chinese ends up being around 10,500 troops.
Of course, this number is probably insufficient for an actual invasion of Taiwan, but this is also ignoring other factors such as the close proximity of the mainland and the possibility of multiple "sorties", the hundreds (almost thousands) of smaller boats in the Chinese inventory, overloading capacity, possible use of "commercial" shipping, etc. In addition, we are also ignoring air transport capabilities. Still, considering the Taiwanese army is over 20 times this size, such an invasion would be unwise for the Chinese at this time. The Chinese are certainly improving their naval and amphibious assets (the Yutings are 1990s production, and more are currently being built), but I doubt that they will attack until their victory is essentially assured, and they are not quite at that point yet.