Background:
This paper describes a curriculum-based multidimensional computerized adaptive test that was developed for Indonesia junior high school Biology.

Materials and methods:
In adherence to the Indonesian curriculum of different Biology dimensions, 300 items was constructed, and then tested to 2238 students. A multidimensional random coefficients multinomial logit model was used to develop multidimensional scales.

Results:
A simulation study based on the item and ability parameters estimated from real data is conducted to evaluate the performance of the proposed Biology-MCAT system. The results show that the bias and standard error of Biology-MCAT system are acceptable.

Conclusions:
It suggests that, this online assessment system can be a model for Indonesian National Examination in future.